Tandem Aldol-lactonization Research Articles

Synthesis of (±)-Protoconstipatic acid methyl ester

Protoconstipatic acid methyl ester was synthesized from the readily available dimethyl itaconate–anthracene adduct as a building block; reacted with the novel protected hydroxy aldehyde via tandem aldol‒lactonization, isomerization and pyrolysis, respectively, producing 23% overall yield.

ChemInform Abstract: Active Methylene Compounds in a Very Effective Approach to 3‐Substituted Isobenzofuranones Through Tandem Aldol/Lactonization Reactions.

AbstractA new, economic, and environmentally benign K2CO3 catalyzed, solvent‐free one‐pot tandem aldol—lactonization to prepare the title compounds is reported.

Active methylene compounds in a very effective approach to 3-substituted isobenzofuranones through tandem aldol/lactonization reactions

In this article we describe a new accessible methodology for the synthesis of isobenzofuran-1(3H)-ones. In this process we exploited an effective, economic, useful and environmentally benign K2CO3 catalyzed, solvent-free one-pot tandem aldol-lactonization reaction between active methylene compounds and methyl 2-carboxy benzaldehyde. A particularly simple work-up and purification procedure are additional advantages addressed to a general green chemistry approach to this important class of heterocyclic compounds.

α‐Haloenol Acetates: Versatile Reactants for Oxetan‐2‐one, Azetidin‐2‐one and Isoxazolidin‐5‐one Synthesis.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

α‐Haloenol Acetates: Versatile Reactants for Oxetan‐2‐one, Azetidin‐2‐one and Isoxazolidin‐5‐one Synthesis

AbstractNew ketene equivalents, namely α‐haloenol acetates, are investigated as both nucleophilic and electrophilic reactants in a tandem aldol–lactonization reaction. Diethylaluminum ethoxide proves to be an efficient promoter for the aldol reaction with a wide range of substrates, including inter alia, aldehydes, ketones, imines, nitrones and oximes, leading to oxetan‐2‐ones, azetidin‐2‐ones and isoxazolidin‐5‐ones. The resultant heterocyclic adducts are common structural elements in numerous compounds of interest as well as key intermediates in the preparation of other functionalities. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Synthesis of both enantiomers of methylenolactocin, nephrosterinic acid and protolichesterinic acid via tandem aldol–lactonization reactions

Both forms of the enantiomerically pure methylenolactocin, nephrosterinic and protolichesterinic acid have been synthesized via tandem aldol–lactonization reactions from corresponding optically active itaconate–anthracene adducts.

The first syntheses of the 1-oxo-2-oxa-5-azaspiro[3.4]octane ring system found in oxazolomycin.

[reaction: see text] L-Proline was utilized to prepare an optically active 1-oxo-2-oxa-5-azaspiro[3.4]octane for the first time. The synthesis of the racemic system, using a tandem aldol-lactonization reaction, is also described. Ruthenium tetroxide oxidation of these compounds afforded the corresponding spiro beta-lactone gamma-lactams.

ChemInform Abstract: Synthesis of β‐Lactones. Part 9. Synthesis of Enantiomerically Pure β‐Lactones by the Tandem Aldol—Lactonization. A Highly Efficient Access to (3S,4S)‐3‐Hexyl‐4‐[(2S)‐2‐hydroxytridecyl]oxetan‐2‐one (IV), the Key Intermediate for the Enzyme Inhibitors Tetrahydrolipstatin (VIa) and Tetrahydroesterastin (VIb).

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.