First Enantioselective Total Synthesis of Both (+)- and (−)-Metachromin A

Abstract

The antineoplastic agent (−)-metachromin A (1) from Hippospongia metachromia has been synthesized in enantiomerically pure form in 13% overall yield. A general convergent synthetic strategy for different metachromins using a 2-alkyloxy-3-sulfonyl-1,3-oxazolidine as a chiral dithienium equivalent is presented.