Synthesis and conformational studies of 9-substituted [3.3]metacyclophane-2,11-diones and conversion to the corresponding [3.3]metacyclophanes

Abstract

Various anti-9-substituted [3.3]MCP-2,11-diones are exclusively obtained by the coupling reaction of the corresponding 1,3-bis(bromomethyl)benzenes and 2,6-bis[2-isocyano-2-(tolylsulfonyl)ethyl]-4- tert-butylbenzenes in dimethylformamide (DMF) with an excess of sodium hydride, from which the corresponding syn-[3.3]MCP are synthesised via anti- syn-isomerisation during the Wolff-Kishner reduction.