Synthesis of a symmetric tetrakis-epoxide from a 3,4-d-mannitol bridged o,o-cyclophane

The coupling reaction of 1,2:5,6-di-O-isopropylidene-d-mannitol with α,α′-dibromoxylene has been reinvestigated. We found reaction conditions leading to the 3,4-d-mannitol bridged o,o-cyclophane 3, free of the 3,4-O-o-xylylene protected mannitol 2. Compound 3 could be converted in 57% yield into tetrakis-epoxide 4.