Cyclobutanone from Methylenecyclopropane via Oxaspiropentane

Cyclobutanone from methylenecyclopropane via oxaspiropentane reactant: 228 g. (2.52 moles) of 3-chloro-2-methyl-1-propene intermediate: methylenecyclopropane intermediate: oxaspiropentane (35%) product: cyclobutanone Keywords: annulation, carbocyclic-[3]; annulation, carbocyclic-[4]; annulation, heterocyclic-[3]; cyclization, condensation; cyclization, oxidative cyclization; epoxide formation; oxidation, miscellaneous; rearrangements; tert-butyl alcohol; tetrahydrofuran; ammonia; stirrers, mercury-sealed