Total Synthesis and Structural Revision of Cephalosporolide J

Herein, we report the first total synthesis of cephalosporolide J, which is a deep sea sediment derived polyketide harboring a unique bicyclo[3.3.0]furanolactone moiety. The adopted synthetic strategy consisted of the alkynylation of γ-lactone with lithium alkynyltrifluoroborate followed by a spiroketalization triggered by hydrogenation of the triple bond. Through this synthesis, the correct structure of cephalosporolide J is shown to be that of the 9-epi stereoisomer of the structure originally proposed.