Single Enantiomer Research Articles

In vitro enantioselective inhibition of the main human CYP450 enzymes involved in drug metabolism by the chiral pesticide tebuconazole

Tebuconazole (TEB) is a chiral triazole fungicide worldwide employed to control plant pathogens and preserve wood. People can be exposed to TEB either through diet and occupational contamination. This work investigates the in vitro inhibitory potential of rac-TEB, S-(+)-TEB, and R-(−)-TEB over the main cytochrome P450 enzymes (CYP450) using human liver microsomes to predict TEB in vivo inhibition potential. The IC50 values showed that in vitro inhibition was enantioselective for CYP2C9, CYP2C19, and CYP2D6, but not for CYP3A4/5. Despite enantioselectivity, rac-TEB and its single enantiomers were always classified in the same category. The inhibition mechanisms and constants were determined for rac-TEB and it has shown to be a mixed inhibitor of CYP3A4/5 (Ki = 1.3 ± 0.3 μM, αKi = 3.2 ± 0.5 μM; Ki = 0.6 ± 0.3 μM, αKi = 1.3 ± 0.3 μM) and CYP2C9 (Ki = 0.7 ± 0.1 μM, αKi = 2.7 ± 0.5 μM), and a competitive inhibitor of CYP2D6 (Ki = 11.9 ± 0.7 μM) and CYP2C19 (Ki = 0.23 ± 0.02 μM), respectively, suggesting that in some cases, rac-TEB has a higher or comparable inhibitory potential than well-known strong inhibitors of CYP450 enzymes, especially for CYP2C9 and CYP2C19. In vitro-in vivo extrapolations (IVIVE) were conducted based on the results and data available in the literature about TEB absorption and metabolism. R1 values were estimated based on the Food and Drug Administration guideline and suggested that in a chronic oral exposure scenario considering the acceptable daily intake dose proposed by the European Food and Safety Authority, the hypothesis of rac-TEB to inhibit the activities of CYP3A4/5, CYP2C9, and CYP2C19 in vivo and cause pesticide-drug interactions cannot be disregarded.

Kinetic Resolution of Racemic Mixtures via Enantioselective Photocatalysis.

Despite the increasing demand for enantiopure drugs in the pharmaceutical industry, currently available chiral separation technologies are still lagging behind, whether due to throughput or to operability considerations. This paper presents a new kinetic resolution method, based on the specific adsorption of a target enantiomer onto a molecularly imprinted surface of a photocatalyst and its subsequent degradation through a photocatalytic mechanism. The current model system is composed of an active TiO2 layer, on which the target enantiomer is adsorbed. A photocatalytic suppression layer of Al2O3 is then grown around the adsorbed target molecules by atomic layer deposition. Following the removal of the templating molecules, molecularly imprinted cavities that correspond to the adsorbed species are formed. The stereospecific nature of these pores encourages enantioselective degradation of the undesired species through its enhanced adsorption on the photocatalyst surface, while dampening nonselective photocatalytic activity around the imprinted sites. The method, demonstrated with the dipeptide leucylglycine as a model system, revealed a selectivity factor of up to 7 and an enrichment of a single enantiomer to 85% from an initially racemic mixture. The wide range of parameters that can be optimized (photocatalyst, concentration of imprinted sites, type of passivating layer, etc.) points to the great potential of this method for obtaining enantiomerically pure compounds, beginning from racemic mixtures.

Efficient enantioresolution of aromatic α-hydroxy acids with Cinchona alkaloid-based zwitterionic stationary phases and volatile polar-ionic eluents

Single enantiomers of mandelic acid (1), 3-phenyllactic acid (2), and 3-(4-hydroxyphenyl)lactic acid (3) are the subject of many fields of investigation, spanning from the pharmaceutical synthesis to that of biocompatible and biodegradable polymers, while passing from the interest towards their antimicrobial activity to their role as biomarkers of particular pathological conditions or occupational exposures to specific xenobiotics. All above mentioned issues justify the need for accurate analytical methods enabling the correct determination of the individual enantiomers. So far, all the developed liquid chromatography (LC) methods were not or hardly compatible with mass spectrometry (MS) detection. In this paper, a commercially available Cinchona-alkaloid derivative zwitterionic chiral stationary phase [that is, the CHIRALPAK® ZWIX(−)] was successfully used to optimize the enantioresolution of compounds 1–3 under polar-ionic (PI) conditions with a mobile phase consisting of an acetonitrile/methanol 95/5 (v/v) mixture with 80 mM formic acid. With the optimized conditions, enantioseparation and enantioresolution values up to 1.46 and 4.41, respectively, were obtained. In order to assess the applicability of the optimized enantioselective chromatography conditions in real-life scenarios and on MS-based systems, a proof-of-concept application was efficiently carried out by analysing dry urine spot samples spiked with 1 by means of a LC-MS system. The (S)<(R) enantiomer elution order (EEO) was established for compounds 1 and 2 by analysing a pure enantiomeric standard of known configuration. This was not possible for 3 because not commercially available. For this compound, the same EEO was identified applying a procedure based on ab initio time-dependent density-functional theory simulations coupled to electronic circular dichroism analyses. Moreover, a molecular dynamics simulation unveiled the role of the phenolic OH in compound 3 in the retention mechanism.

Hemi-synthesis of novel (S)-carvone hydrazone from Carum carvi L. essential oils: Structural and crystal characterization, targeted bioassays and molecular docking on human protein kinase (CK2) and Epidermal Growth factor Kinase (EGFK)

Polyfunctional N,O,O,N-type ligands such as the oxalyl dihydrazide (ODH) may induce formation of mono-, di-, and polynuclear complexes with natural monoterpene ketones, involving ligand bridging and Oxo-bridging. In this context, a novel chiral dihydrazone is designed through hemi-synthesis process by reacting oxalyldihydrazide (ODH) with (s)-carvone, the major compound of caraway's seeds essential oil. The C = N imine bi-condensation is performed without prior isolation of the natural (s)-carvone and the resulting (s)-carvone dihydrazone (s-CHD) is structurally characterized by Single-crystal X-ray diffraction, 2D-NMR spectroscopy and chiral LCMS analysis to confirm the formation of a single pure enantiomer. In-vitro cell-based assays were conducted on normal fibroblast (L929) using a presBlue (PB) fluorescence quantification method of cell-viability and by sulforhodamine B calorimetric cytotoxicity assays to determine the anti-proliferative effect on four human tumoral lines (NCI-H460, Hela, HepG2 and MCF-7) and normal PLP2. Anti-inflammatory assays were determined through NO production by Maurine LPS-stimulated macrophages (RAW 264.7). The (s)-CHD has no effect on normal cells viability (>88%) and PLP2 (GI50= 326 ug/mL), while a moderate (∼55%) to significant (∼63%) antigrowth potential was recorded against HepG2, Hela and MCF-7 tumor cell lines, where RAW 264.7 was feebly sensitive. A molecular docking was performed using Autodock vina software on the protein kinase CK2 and Epidermal Growth factor Kinase proteins EGFK and the dock scores allowed to identify significant binding affinities (lower ΔG and Ki values) and potential hydrophilic/hydrophobic interactions with (s)-CHD comparing to the clinical ellipticine as potential ligands. Molecular docking suggests that (s)-CHD possesses high affinity towards the kinase domain receptors CK2 and EGFR, being able to bind to the ATP region.

Comparisons of β-Hairpin Propensity Among Peptides with Homochiral or Heterochiral Strands.

Assemblies of racemic β-sheet-forming peptides have attracted attention for biomedical applications because racemic forms of peptides can self-associate more avidly than do single enantiomers. In 1953, Pauling and Corey proposed "rippled β-sheet" modes of H-bond-mediated interstrand assembly for alternating L- and D-peptide strands; this structural hypothesis was complementary to their proposal of "pleated β-sheet" assembly for L-peptides. Although no high-resolution structure has been reported for a rippled β-sheet, there is strong evidence for the occurrence of rippled β-sheets in some racemic peptide assemblies. Here we compare propensities of peptide diastereomers in aqueous solution to form a minimum increment of β-sheet in which two antiparallel strands associate. β-Hairpin folding is observed for homochiral peptides with aligned nonpolar side chains, but no β-hairpin population can be detected for diastereomers in which one strand contains L residues and the other contains D residues. These observations suggest that rippled β-sheet assemblies are stabilized by interactions between β-sheet layers rather than interactions within these layers.

Theoretical electronic circular dichroism investigations of chiral amino acids and development of separation and identification methods independent of standards

Through an appropriate computational protocol and environmental simulation, a satisfactory fit was observed for the theoretical electronic circular dichroism (ECD) spectra of 19 chiral amino acids (AAs), which correspondeds to the forms of the AAs in aqueous solution. Methods for enantioseparation of these chiral AAs by capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) were developed. Combining ECD with chromatographic separation methods, enantiomers were identified and quantified independent of a single enantiomer standard.

Cu catalysts do chiral amide synthesis

A pair of copper catalysts can create chiral amides in a new, light-driven process, offering a useful alternative to the standard method for making these staples of medicinal chemistry ( Nature 2021, DOI: 10.1038/s41586-021-03730-w ). “Amides are ubiquitous functional groups in bioactive molecules, such as peptides,” says Gregory C. Fu , a chemist at the California Institute of Technology who co-led the work. The conventional route to chiral amides involves producing a single enantiomer of an amine and then reacting it with a carboxylic acid derivative. In contrast, the Caltech team’s method needs only a single step and controls the stereochemistry of the amide as it forms. The reaction relies on two different Cu catalysts and combines an amide with an alkyl bromide to form a chiral secondary amide—where the nitrogen atom is bonded to a hydrogen and two carbons, one of which is chiral. The first catalyst is a

Large-Scale Cyclopropanation of Butyl Acrylate with Difluorocarbene and Classical Resolution of a Key Fluorinated Building Block

To address challenges in the preparation of a key building block containing a difluorocyclopropane moiety, we have developed a new protocol for difluorocarbene generation that relies on a Krapcho-type dealkylation of ethyl bromodifluoroacetate (EBDFA), an inexpensive and readily available fluorinated feedstock. Application of DoE and kinetic modeling was used to understand key reaction parameters and identify an optimal process. We report two variants of this procedure that offer different processing advantages and that have both been scaled successfully multiple times to deliver hundreds of kilograms of the resulting difluorocyclopropane. To access a single enantiomer of the target compound, we have also developed a classical resolution strategy and recycling protocol for the undesired enantiomer to replace previous chromatographic methods for separation.

Preparation and characterized study of new molecularly imprinted polymers for determination Cocaine by GC-Mass based on different Functional Monomers

Molecularly imprinted polymers (MIP) Showing high selectivity and affinity with an increasingly increasing analysis is now seen in the predetermined molecule (template) Furthermore, it is difficult to refine imprinted items due to the fact that there are multiple Variables to worry about, Any or all of this could have a likely effect on the chemical, Properties of the imprinted components in morphological and molecular identification, it is a rapidly emerging technique for the preparation of polymers having unique molecular recognition properties for a given compound MIP synthesis is a relatively easy and inexpensive process, either for its analogues or for a single enantiomer. For the selective extraction of COC and BE from urine samples, newly synthesized molecularly imprinted polymer sorbents were proposed in this report. using a functional monomer which To build a monolithic solid-phase micro extraction (SPME) fiber, Styrene and Allyl chloride are used, as well as Ethylene glycol methacrylate (EGDMA) as a suitable cross-linker and Cocaine as a template. A non-imprinted polymer was created by preparing a polymer without selective binding sites (NIP). All of these analytical procedures were utilized to extract, preconcentrate, and selectively determine Cocaine and its derivatives (SPME) with gas chromatography and mass spectrometry (GC/MS). sturdiness, The manufactured fiber's basic and vital role in SPME is due to its stability and durability. The samples were taken from a suspected cocaine abuser who was donated by the medico-legal directorate (Baghdad, Iraq). The analytes were monitored using a (GC MS), UV-vis, Scanning electron microscopy (SEM), and FTIR. The relative standard deviations (RSD percent ) for two patients' repeated studies for three measurements vary from (1.587-4.545) percent (at 20-100 ppm of Cocaine). Cocaine relative recoveries in human urine samples spiked with the drug are in the range of (102-105).

Cobalt-Catalyzed Chemo- and Enantioselective Hydrogenation of Conjugated Enynes.

Asymmetric hydrogenation is one of the most powerful methods for the preparation of single enantiomer compounds. However, the chemo- and enantioselective hydrogenation of the relatively inert unsaturated group in substrates possessing multiple unsaturated bonds remains a challenge. We herein report a protocol for the highly chemo- and enantioselective hydrogenation of conjugated enynes while keeping the alkynyl bond intact. Mechanism studies indicate that the accompanying Zn2+ generated from zinc reduction of the CoII complex plays a critical role to initiate a plausible CoI /CoIII catalytic cycle. This approach allows for the highly efficient generation of chiral propargylamines (up to 99.9 % ee and 2000 S/C) and further useful chemical transformations.

Cobalt‐Catalyzed Chemo‐ and Enantioselective Hydrogenation of Conjugated Enynes

AbstractAsymmetric hydrogenation is one of the most powerful methods for the preparation of single enantiomer compounds. However, the chemo‐ and enantioselective hydrogenation of the relatively inert unsaturated group in substrates possessing multiple unsaturated bonds remains a challenge. We herein report a protocol for the highly chemo‐ and enantioselective hydrogenation of conjugated enynes while keeping the alkynyl bond intact. Mechanism studies indicate that the accompanying Zn2+ generated from zinc reduction of the CoII complex plays a critical role to initiate a plausible CoI/CoIII catalytic cycle. This approach allows for the highly efficient generation of chiral propargylamines (up to 99.9 % ee and 2000 S/C) and further useful chemical transformations.

Base-Catalyzed, Solvent-Free Synthesis of Rigid V-Shaped Epoxydibenzo[b,f][1,5]diazocines.

A novel method for the synthesis of epoxydibenzo[b,f][1,5]diazocines exhibiting a V-shaped molecular architecture is reported. The unique approach is based on unprecedented base-catalyzed, solvent-free autocondensation and cross-condensation of fluorinated o-aminophenones. The structure of the newly synthesized diazocines was confirmed independently by X-ray analysis and chiroptical methods. The rigidity of the diazocine scaffold allowed for the separation of the racemate into single enantiomers that proved to be thermally stable up to 140 °C. Furthermore, the inertness of the diazocine scaffold was demonstrated by performing a series of typical transformations, including transition metal-catalyzed reactions, proceeding without affecting the bis-hemiaminal subunit.

Meso-tetra(dioxanyl)porphyrins: Neutral, low molecular weight, and chiral porphyrins with solubility in aqueous solutions

The synthesis of the low-molecular weight, meso-tetra(dioxan-2-yl)porphyrin with considerable solubility in aqueous solution is described. The key intermediate dioxan-2-carbaldehyde is accessible in either racemic or in stereo-pure forms from commercially available starting materials in three steps. Using 4 × 1 or 2 + 2-type syntheses provide the porphyrin in modest yields. While the racemic aldehyde created an intractable mixture of diastereomers, the enantiopure aldehyde created a single enantiomer of the target porphyrin. The porphyrin was spectroscopically characterized. As its free base or zinc complex, it showed excellent solubility properties in organic and aqueous solvents, though free water-solubility was not achieved. The work expands on the availability of chiral porphyrins and neutral porphyrins with considerable solubility in aqueous solution.

Enantiomeric alkynyl-protected Au10 clusters with chirality-dependent radiotherapy enhancing effects

Due to the homo-chirality preference of human body to most of chiral species, synthesizing enantiopure drugs and investigating the pharmacological activity of each enantiomer would have great meaning. However, the influence of chirality at nanoscale on the ability to enhance radiotherapy has not been studied. Herein, a pair of enantiomeric alkynyl-protected L/D-Au10(C13H17O5)10 nanoclusters (L/D-AuNCs) with strong chirality (g value up to 3.6 × 10-3) and circular polarization luminescence (glum ≈ 3 × 10-3) are prepared and applied as radiosensitizers. As a consequence, D-AuNCs exhibit better radiosensitization effect in vitro, which is confirmed by research on mechanisms including reactive oxygen species (ROS) burst mediated DNA breakage, cell cycle arrest and up-regulation of apoptotic protein expression. In vivo antitumor studies manifest that tumors treated with D-AuNCs and X-ray show a volume decrease of 51% compared with X-ray (4 Gy) only group. This work not only enriches the family of gold-based nano-radiosensitizers, but also further proves the significance of chirality in biomedicine.

Efficacy of Fenfluramine and Norfenfluramine Enantiomers and Various Antiepileptic Drugs in a Zebrafish Model of Dravet Syndrome

Dravet syndrome (DS) is a rare genetic encephalopathy that is characterized by severe seizures and highly resistant to commonly used antiepileptic drugs (AEDs). In 2020, FDA has approved fenfluramine (FFA) for treatment of seizures associated with DS. However, the clinically used FFA is a racemic mixture (i.e. (±)-FFA), that is substantially metabolized to norfenfluramine (norFFA), and it is presently not known whether the efficacy of FFA is due to a single enantiomer of FFA, or to both, and whether the norFFA enantiomers also contribute significantly. In this study, the antiepileptic activity of enantiomers of FFA (i.e. (+)-FFA and (−)-FFA) and norFFA (i.e. (+)-norFFA and (−)-norFFA) was explored using the zebrafish scn1Lab−/− mutant model of DS. To validate the experimental conditions used, we assessed the activity of various AEDs typically used in the fight against DS, including combination therapy. Overall, our results are highly consistent with the treatment algorithm proposed by the updated current practice in the clinical management of DS. Our results show that (+)-FFA, (−)-FFA and (+)-norFFA displayed significant antiepileptic effects in the preclinical model, and thus can be considered as compounds actively contributing to the clinical efficacy of FFA. In case of (−)-norFFA, the results were less conclusive. We also investigated the uptake kinetics of the enantiomers of FFA and norFFA in larval zebrafish heads. The data show that the total uptake of each compound increased in a time-dependent fashion. A somewhat similar uptake was observed for the (+)-norFFA and (−)-norFFA, implying that the levo/dextrotation of the structure did not dramatically affect the uptake. Significantly, when comparing (+)-FFA with the less lipophilic (+)-norFFA, the data clearly show that the nor-metabolite of FFA is taken up less than the parent compound.

Cocrystals of Praziquantel: Discovery by Network-Based Link Prediction.

Cocrystallization has been promoted as an attractive early development tool as it can change the physicochemical properties of a target compound and possibly enable the purification of single enantiomers from racemic compounds. In general, the identification of adequate cocrystallization candidates (or coformers) is troublesome and hampers the exploration of the solid-state landscape. For this reason, several computational tools have been introduced over the last two decades. In this study, cocrystals of Praziquantel (PZQ), an anthelmintic drug used to treat schistosomiasis, are predicted with network-based link prediction and experimentally explored. Single crystals of 12 experimental cocrystal indications were grown and subjected to a structural analysis with single-crystal X-ray diffraction. This case study illustrates the power of the link-prediction approach and its ability to suggest a diverse set of new coformer candidates for a target compound when starting from only a limited number of known cocrystals.

Photochemical Probe Identification of a Small-Molecule Inhibitor Binding Site in Hedgehog Acyltransferase (HHAT)*.

The mammalian membrane‐bound O‐acyltransferase (MBOAT) superfamily is involved in biological processes including growth, development and appetite sensing. MBOATs are attractive drug targets in cancer and obesity; however, information on the binding site and molecular mechanisms underlying small‐molecule inhibition is elusive. This study reports rational development of a photochemical probe to interrogate a novel small‐molecule inhibitor binding site in the human MBOAT Hedgehog acyltransferase (HHAT). Structure‐activity relationship investigation identified single enantiomer IMP‐1575, the most potent HHAT inhibitor reported to‐date, and guided design of photocrosslinking probes that maintained HHAT‐inhibitory potency. Photocrosslinking and proteomic sequencing of HHAT delivered identification of the first small‐molecule binding site in a mammalian MBOAT. Topology and homology data suggested a potential mechanism for HHAT inhibition which was confirmed by kinetic analysis. Our results provide an optimal HHAT tool inhibitor IMP‐1575 (K i=38 nM) and a strategy for mapping small molecule interaction sites in MBOATs.

Photochemical Probe Identification of a Small-Molecule Inhibitor Binding Site in Hedgehog Acyltransferase (HHAT).

The mammalian membrane-bound O-acyltransferase (MBOAT) superfamily is involved in biological processes including growth, development and appetite sensing. MBOATs are attractive drug targets in cancer and obesity; however, information on the binding site and molecular mechanisms underlying small-molecule inhibition is elusive. This study reports rational development of a photochemical probe to interrogate a novel small-molecule inhibitor binding site in the human MBOAT Hedgehog acyltransferase (HHAT). Structure-activity relationship investigation identified single enantiomer IMP-1575, the most potent HHAT inhibitor reported to-date, and guided design of photocrosslinking probes that maintained HHAT-inhibitory potency. Photocrosslinking and proteomic sequencing of HHAT delivered identification of the first small-molecule binding site in a mammalian MBOAT. Topology and homology data suggested a potential mechanism for HHAT inhibition which was confirmed by kinetic analysis. Our results provide an optimal HHAT tool inhibitor IMP-1575 (K i=38 nM) and a strategy for mapping small molecule interaction sites in MBOATs.

Evaluation of Trials Comparing Single-Enantiomer Drugs to Their Racemic Precursors

Chiral switching, a strategy in which drug manufacturers develop a single-enantiomer formulation of a drug to be substituted for a racemic formulation, allows manufacturers to maintain market exclusivity for drugs losing patent protection, even without demonstrating superior efficacy or safety. To identify and characterize all randomized clinical trials (RCTs) directly comparing a Food and Drug Administration (FDA)-approved single-enantiomer drug against a previously approved racemic drug for 1 or more efficacy or safety end points. Drugs were identified using the Drugs@FDA database. Randomized clinical trials were identified using Ovid MEDLINE (1949 to October 22, 2019), Ovid Embase (1974 to October 22, 2019), Web of Science Core Collection (all years), ClinicalTrials.gov, and Cochrane Central Registry of Controlled Trials (CENTRAL, Wiley, Issue 8 of 12, October 22, 2019). Trials were characterized as favoring the single-enantiomer or racemic drugs based on whether the primary efficacy, secondary efficacy, and safety end points achieved each study's defined significance level (eg, P < .05). Trials were characterized as favoring neither drug if no statistically significant differences were reported for any end point or if both drugs were found to be superior for 1 or more separate end points. Fifteen FDA-approved single-enantiomer drugs were identified with racemic precursors approved in the US or Europe. For 3 single-enantiomer racemic drug pairs, no RCTs directly comparing the drugs were identified. For the remaining 12 pairs, 185 RCTs comparing efficacy or safety of the drug pairs were identified, 124 (67.0%) of which studied 1 pair (levobupivacaine/bupivacaine). There were 179 RCTs directly comparing drug pairs using efficacy end points, of which 23 (12.8%) favored the single enantiomer based on primary efficacy end point results. There were 124 RCTs directly comparing drug pairs using safety end points, of which 17 (13.7%) favored the single-enantiomer drug. For 9 of the 15 single-enantiomer drugs (60.0%), no RCTs were identified providing evidence of improved efficacy, based on primary end point results, or safety as compared with their racemic precursors. The results of this systematic review suggest that most newly marketed FDA-approved single-enantiomer drugs are infrequently directly compared with their racemic precursors, and when compared, they are uncommonly found to provide improved efficacy or safety, despite their greater costs.

Lipase Catalyzed Synthesis of Enantiopure Precursors and Derivatives for β-Blockers Practolol, Pindolol and Carteolol

Sustainable methods for producing enantiopure drugs have been developed. Chlorohydrins as building blocks for several β-blockers have been synthesized in high enantiomeric purity by chemo-enzymatic methods. The yield of the chlorohydrins increased by the use of catalytic amount of base. The reason for this was found to be the reduced formation of the dimeric by-products compared to the use of higher concentration of the base. An overall reduction of reagents and reaction time was also obtained compared to our previously reported data of similar compounds. The enantiomers of the chlorohydrin building blocks were obtained by kinetic resolution of the racemate in transesterification reactions catalyzed by Candida antarctica Lipase B (CALB). Optical rotations confirmed the absolute configuration of the enantiopure drugs. The β-blocker (S)-practolol ((S)-N-(4-(2-hydroxy-3-(isopropylamino)propoxy)phenyl)acetamide) was synthesized with 96% enantiomeric excess (ee) from the chlorohydrin (R)-N-(4-(3-chloro-2 hydroxypropoxy)phenyl)acetamide, which was produced in 97% ee and with 27% yield. Racemic building block 1-((1H-indol-4-yl)oxy)-3-chloropropan-2-ol for the β-blocker pindolol was produced in 53% yield and (R)-1-((1H-indol-4-yl)oxy)-3-chloropropan-2-ol was produced in 92% ee. The chlorohydrin 7-(3-chloro-2-hydroxypropoxy)-3,4-dihydroquinolin-2(1H)-one, a building block for a derivative of carteolol was produced in 77% yield. (R)-7-(3-Chloro-2-hydroxypropoxy)-3,4-dihydroquinolin-2(1H)-one was obtained in 96% ee. The S-enantiomer of this carteolol derivative was produced in 97% ee in 87% yield. Racemic building block 5-(3-chloro-2-hydroxypropoxy)-3,4-dihydroquinolin-2(1H)-one, building block for the drug carteolol, was also produced in 53% yield, with 96% ee of the R-chlorohydrin (R)-5-(3-chloro-2-hydroxypropoxy)-3,4-dihydroquinolin-2(1H)-one. (S)-Carteolol was produced in 96% ee with low yield, which easily can be improved.