Enantioselective synthesis of 15-epi-haterumalide NA methyl ester and revised structure of haterumalide NA.

[structure: see text] The enantioselective synthesis of the enantiomer of the haterumalide NA methyl ester, a cytotoxic macrolide from an Okinawan sponge, was achieved from the threitol derivative in 26 steps. The key steps are the stereoselective construction of a chloroolefin unit and the intramolecular Reformatsky-type reaction. This synthesis revised the absolute stereochemistry of haterumalide NA.