Synthesis Of Amino Ketones Research Articles

Stereoselective synthesis of amino ketones of the pinane series

At present, enantiomerically pure α-pinene and camphor derivatives are widely used in asymmetric syntheses as chiral auxiliaries [1], building blocks [2, 3], and chiral ligands [4]. For example, terpene amino alcohols derived from 2α-hydroxypinan-3-one, were studied as enantioselective ligands in the ruthenium-catalyzed reduction of acetophenone [5], while palladium chelates with bornane diimines and diamines efficiently catalyzed asymmetric allylic substitution reactions [6]. According to published data, search for new enantiomerically pure ligands on the basis of commercially available initial compounds is a topical problem. We previously reported the synthesis of chiral imines and amines from 2α-hydroxypinan-3-one [7]. The resulting nitrogen-containing derivatives were successfully used as ligands to obtain various palladium complexes [8, 9].

New oxidative reactions of 1,2,3,6-tetrahydropyridines: imination, lactamination and decyclisation in the presence of potassium permanganate

A novel oxidative imination reaction of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine 1a by 4-nitroaniline/potassium permanganate has been found to occur yielding 2-(4-nitrophenyl)imino-1,2,5,6-tetrahydropyridine 4; in the absence of nitroaniline the shorter reaction time allows the reaction to be stopped at the unsaturated lactam 5 formation stage; the oxidation of 1a hydrochloride leads to 1-( N -formyl- N -methyl)amino-3-phenylpropan-2-one 6 via decyclisation–elimination steps, providing a new method for N -formyl-substituted aminoketone synthesis.

Influence of puromycin and chloramphenicol on aminoketone synthesis (δ-aminolevulinic acid synthesis) induction by allylisopropylacetamide in rat liver

In vitro induction of aminoketone synthesis (AKS) by allylisopropylacetamide (AIA) in liver slices from 30 day-old male rats was reversibly inhibited by puromycin (50 micrograms/ml incubation mixture). Normal AKS was initially stimulated and thereafter blocked. Chloramphenicol (350 micrograms/ml) inhibited AIA mediated induction of AKS only partially and only when added 1 h before AIA to the incubation mixture. In vivo puromycin (3 i.p. injections of 15 mg/kg in 1 h intervals) did not influence AKS or AIA mediated AKS induction in newborn rats, whereas chloramphenicol (500 mg/kg s.c. 30 min prior to AIA) inhibited AIA mediated AKS induction in newborn rats. In 40 day-old rats pretreatment with chloramphenicol completely inhibited AKS induction by 200 mg/kg AIA.

Influence of cycloheximide on normal and induced δ-aminolevulinie acid synthetase (aminoketone synthesis) of rat liver in vivo and in vitro

2 and 5 mg/kg cycloheximide given i.p. 30 minutes prior to the inducer allylisopropylacetamide (AIA) diminished or prevented the enhancement of delta-aminolevulinic acid synthetase (ALAS) activity in newborn rats. In adult rats the small AIA effect 24 hours after pretreatment was enhanced by 2 mg/kg cycloheximide i.p., when the inhibitor was injected 2 hours prior to the inducer. The basic aminoketone synthesis was inhibited by cycloheximide alone. 150-600 microgram/ml cycloheximide had no effect on the aminoketone synthesis of rat liver slices in vitro during 4 hours of incubation. The in vitro induction by 0.6 mg/ml AIA was enhanced by cycloheximide, if the inducer was added 1 hour after preincubation with cycloheximide. It is supposed, that the cytoplasmically localized precursor-ALAS is activated at the beginning of the induction process prior to the initiation of de novo enzyme synthesis, at least in vitro.

Amino ketone synthesis in avian erythrocytes.

1. The relative rates of synthesis of aminolaevulate and aminoacetone by particles prepared from avian erythrocytes were measured under various conditions. 2. The production of both amino ketones by fresh particles was about three times greater in anaemia caused by phenylhydrazine and acetylphenylhydrazine than in anaemia caused by removal of 20-30ml. of blood. 3. The synthesis of aminolaevulate by freeze-dried particles decreased more than that of aminoacetone in the absence of added pyridoxal phosphate, in the presence of cyanide and of tris buffer, and after preincubation of the erythrocyte particles. Other differences in the rates of synthesis of the two amino ketones were observed after (a) incubation of particles at different temperatures and (b) storage of homogenized freeze-dried particles at different pH values. 4. It is suggested that these differences in the production of the two amino ketones are due to the presence of two amino ketone synthetases or to two or more isoenzymes of aminolaevulate synthetase. 5. The metabolic significance of aminoacetone in erythrocytes is discussed.