ChemInform Abstract: Synthesis of Some Substituted Oxaspiro[4,5]decanenones by Way of Intermolecular Diels—Alder Reaction of Alkylidene 2,3‐Dimethoxybutenolides Obtained from L‐Ascorbic Acid.

Abstract

Synthesis of Some Substituted Oxaspiro [4,5]decanenones by Way of Intermolecular Diels-Alder Reaction of Alkylidene 2,3-Dimethoxybutenolides Obtained from L-Ascorbic Acid.-The butenolide (Va), obtained from L-ascorbic acid (I), is treated with diester (VII) in order to obtain spirolactone (VI), a skeleton incorporated in several natural products. However, intramolecular cycloaddition of (Va) is observed instead forming the title compounds (VIII) and (IX) with the endo isomer as the main product. - (KHAN, M. A.; BOYES, S. A.; ADAMS, H.; Molecules 1 (1996) 27-36; Div. Chem., Health Res. Inst., Sheffield Hallam Univ., Sheffield S1 1WB, UK; EN)