Total Syntheses of Compactin (ML-236B) and Monacolin K (Mevinolin)

Abstract

Convergent and enantiospecific syntheses of compactin (1 a) and mevinolin (1 b), potent competitive inhibitor of HMG-CoA reductase, have been achieved via asymmetric intramolecular Diels-Alder reaction of acyclic (E, E, E)-trienone 4 leading to trans-octalone 3, a common intermediate for congeners. Chirality of C13 in 4 was designed to induce the four asymmetric centers with desired configuration by this reaction: the chirality controlled the approach of the dienophile from a single diastereotopic face. Trienone 4 was expeditiously constructed by the combination of two segments 5 and 6. Enantio- and stereo-specific synthesis of 6, a chiral 1, 3, 5-trio 1 derivative, rested on the two novel methodologies, i. e, the convenient asymmetric reduction of β-keto carboxylate 19 d with baker's yeast and the regio- and stereo-selective iodofunctionalization (1, 3-asymmetric induction) of homoallylic carbamate. Preparation of 5 in its optically active form was accomplished by the elaboration of readily available γ-lactone 12. © 1983, The Society of Synthetic Organic Chemistry, Japan. All rights reserved.