Synthesis of α-Halobutenolides Using the Nucleophilicity of Magnesium Alkylidene Carbenoids
作者:Tsuyoshi Satoh、Tsutomu Kimura、Kazuki Fukuda、Gaku Kashiwamura
DOI:10.3987/com-14-s(k)60
日期:——
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.