Total synthesis of (±)-silphinene: Non photochemical cyclobutenic route to a crucial intermediate

Article abstract of DOI:10.1016/S0040-4020(96)01159-3

The cyclobutenic ester 1, readily available by thermal [2+2] cycloaddition of the silyl enol ether derived from cyclopentanone with ethyl propynoate, is easily transformed into the diquinanic alcohol 3 via the bicycle [2.1.0] pentane intermediate 2. After