Synthesis of α-Halobutenolides Using the Nucleophilicity of Magnesium Alkylidene Carbenoids
摘要:
alpha-Halobutenolides were synthesized from halomethyl p-tolyl sulfoxides, alpha-bromoketones, and phenyl chloroformate in three steps using the nucleophilicity of magnesium alkylidene carbenoids. The reaction of alpha-bromoketones with [halo(p-tolylsulfinyl)methyl]lithiums and the subsequent basification of the reaction mixture using an aqueous NaOH solution afforded 1-chloro-3-hydroxyprop-1-enyl p-tolyl sulfoxides in 83-99% yield. A phenoxycarbonyl group was then introduced to the hydroxyl group of the sulfoxides by reacting with phenyl chloroformate in the presence of pyridine. The sulkodde/magnesium exchange reaction of the cyclization precursors with i-PrMgCl center dot LiCl led to the formation of alpha-halobutenolides in moderate to good yields.
Total synthesis of rubrolide M and some of its unnatural congeners
作者:Fabio Bellina、Chiara Anselmi、Renzo Rossi
DOI:10.1016/s0040-4039(02)00202-2
日期:2002.3
Two protocols have been developed for the Pd-catalyzed regioselective synthesis of 4-aryl-3-chloro-2(5H)-furanones starting from 3,4-dichloro-2(5H)-furanone. These monochloro derivatives have then been used as precursors to (Z)-4-aryl-5-[1-(aryl)methylidene]-3-chloro-2(5H)-furanones including naturally-occurring rubrolide M.