Asymmetric synthesis of bicyclo[4.3.0]nonan-8-ones by intramolecular Pauson-Khand reaction

Abstract

The intramolecular Pauson-Khand reaction of (E)-1-alkoxy-1-octen-7-ynes derived from (1S,2R)-2-phenylcyclohexanol is described. 7-Alkoxybicyclo[4.3.0]non-1(9)-en-8-ones are obtained in yields up to 65% and with diastereoselectivities higher than 10:1. The absolute configuration of the major diastereomer obtained has been ascertained and can be rationalized on the basis of the preferential conformation of the precursor.