Simple synthesis of substituted 3-oxabicyclo[3.1.0]hexan-2-ones and their rearrangement in the presence of lithium iodide
摘要:
2-Alkenylidenemalonic ester monoepoxides react with organolithium and organomagnesium compounds to give 1-ethoxycarbonyl-4-alkyl-6-alkenyl(alkyl, aryl, alknyl)-3-oxabicyclo[3.1.0]hexan-2-ones in high yields. The latter, when an alkenyl fragment is present, undergo rearrangement in the presence of LiI to substituted 1-ethoxycarbonyl-3-oxabicyclo[3.3.0]-6-octen-2-ones or 3-(1,3-butadienyl)-4-butanolides.