Regioselectivity and diastereoselectivity in the phase transfer catalysed Michael addition of 2-phenylcyclohexanone

Regioselectivity and diastereoselectivity in the Michael addition of 2-phenylcyclohexanone to bulky alpha,beta-unsaturated ketones can be controlled by carefully selecting the reaction conditions. Solvent-free solid-liquid PTC using tetrabutylammonium bromide as catalyst and potassium tertbutoxide as base leads to high de (up to 99%) of the 2,6-disubstituted regioisomer, which is, a priori, the unexpected isomer. (C) 1997 Elsevier Science Ltd.