Bicyclo[2.2.2]octane-2-spirocyclohexanes, Part 1. Production and Structure of Spirodiisophora-3′,6-dione

Abstract

The bicyclo[2.2.2]octane-2-spirocycylohexane structure o f dimers arising from 3-methylcyclohex-2-enones by sodamide-catalyzed self-condensation is established by a study of the 3′,6-dione and 3′-hydroxy-6-ketone by the 13C NMR two-dimensional spectral (INADEQUATE) technique. The 3′,6-dione, the ultimate source of all other compounds of this series, is obtained by an improved procedure. Only one of its keto-groups reacts with ketonic reagents, resulting exclusively in 3′-monosubstituted derivatives