A direct carbometallation-stereoselective cycloaddition-ring closing metathesis route to the tricyclic ABC core of taxoids

Abstract

The synthesis of the tricyclic ABC ring-system of Taxol® (paclitaxel) is described. This direct route involves sequential reactions employing the carbometallation of a propargyl alcohol, followed by a cis-alkene tether controlled stereoselective intramolecular Diels-Alder reaction to generate the AB-ring system and ring closing metathesis (RCM) of the pendant allyl substituents to construct the C ring.