A Concise and Stereospecific One-Shot Synthesis of Bicyclo[3.3.1]nonenols from Dimethyl 1,3-Acetonedicarboxylate and Enals via the Sequential Michael Addition−Intramolecular Aldolization

Abstract

The reactions of dimethyl 1,3-acetonedicarboxylate 1 with enals 2 proceeded very smoothly in the presence of a catalytic amount of tetrabutylammonium fluoride or piperidine in THF at room temperature, giving the corresponding bicyclo[3.3.1]nonane derivatives 3 in high yields. Both of the two fused rings of 3 are newly constructed from the starting two acyclic substrates via the sequential Michael addition−intramolecular aldolization in one shot.