Process for the preparation of 2-oxa-bicyclo [3.3.0] octane derivatives and products produced thereby

摘要

The invention relates to a process for the preparation of 2-Oxabicyclo[3.3.0]octane derivatives of the general formula <IMAGE> I wherein R1, R2, R3 and R5 represent organic radicals and R2 and R3 also may represent hydrogen and wherein R4 is an acyl group or an tri-organo-silyl group and to the compounds of formula I produced by the process of the invention which compounds are valuable intermediates for the preparation of pharmacologically active compounds. The process of the invention comprises reacting a compound of the formula <IMAGE> II wherein R14 is lower alkyl or phenyl with a compound of the formula <IMAGE> III wherein R15 is trimethylsilyl or lower alkanoyl in an inert solvent at temperatures from about -80 DEG C. to about +60 DEG C. in presence of one or more Lewis acids.