A Convergent Approach for the Synthesis of C14-C26 Fragment of Anticancer Drug Eribulin Mesylate

The stereoselective synthesis of C14-C26 fragment of eribulin is reported in a convergent way by coupling of fragment C14- C19 with fragment C20-C26 that are accessible from commercially available raw materials crotonic acid and 1,4-butanediol. The key steps involved in this practical approach are Hosomi-Sakurai asymmetric alkylation, Maruoka allylation, Noyori reduction, silver-catalyzed one-pot rearrangement, and intramolecular cyclization.