A new route to α-methylenelactones, important structural subunits of many natural products, has been developed using the nitrile oxide derived from 2-nitroethanol.
A NEW SYNTHETIC ROUTE TO α-METHYLENE AND β-METHYLENE-γ-BUTYROLACTONES VIA HOMOLYTIC CARBOCYCLIZATION
作者:Osamu Moriya、Makoto Okawara、Yoshio Ueno
DOI:10.1246/cl.1984.1437
日期:1984.8.5
α-Methylene-γ-butyrolactones were prepared using butoxyallene via stereoselective homolytic carbocyclization of vinyl radicals, similarly, β-methylene analogues were also prepared.
Stable organozinc compounds derived from alkyl 3-alkyl 2-(bromomethyl) propenoates reacted with ketones and aldehydes to give alpha-methylene gamma-butyrolactones in excellent yields. Different reaction parameters were studied and some transition states were proposed.