Synthesis of 5-alkylidene-2,5-dihydropyrrol-2-ones based on cyclizations of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with oxalyl chloride
作者:Christian Haase、Peter Langer
DOI:10.1016/j.tet.2009.03.102
日期:2009.6
The acid-mediated reaction of amines with γ-alkylidenebutenolides, readily available by cyclization of 1,3-bis(silyloxy)-1,3-butadienes with oxalylchloride, allows a convenient synthesis of a variety of 5-alkylidene-2,5-dihydropyrrol-2-ones. The configuration of the exocyclic double bond of the products depends on the substitution pattern of the products.
Regio- and Stereoselective Synthesis ofγ-Alkylidenebutenolides by Cyclization of Dilithiated 1,3-Dicarbonyl Compounds withN,N′-Dimethoxy-N,N′-dimethylethane- diamide
The remarkably simple synthesis of γ-alkylidenebutenolides 3 is achieved by cyclization of the dilithiated 1,3-dicarbonyl compounds 1 with N,N'-dimethoxy-N,N'-dimethylethanediamide (2). This regio- and stereoselective cyclization provides a route to a wide range of butenolides, which are of pharmacological relevance and of importance for natural product synthesis.
Synthesis of γ-Lactones and Ascorbic Acid Analogues by Diastereoselective Hydrogenation of α-Hydroxy-γ-alkylidenebutenolides
The cyclization of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with oxalyl chloride afforded functionalized gamma-alkylidene-alpha-hydroxybutenolides, which were transformed into cis-configured gamma-lactones by diastereoselective hydrogenation.((C) Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).