Divergent synthesis of cytotoxic styryl lactones related to goniobutenolides A and B, and to crassalactone D.

Goniobutenolides A (1) and B (2), crassalactone D (3), 4-epi-crassalactone D (4), and the corresponding 7-epimers have been synthesized starting from d-glucose. The key step in the synthesis of 1 and 2 is a new one-pot sequence comprised of a Z-selective Wittig olefination/lactonization/β-elimination. Preparation of 3 and 4 included the final 5-endo-trig spirocyclization of 1 and 2. The synthesized products were evaluated for their in vitro antiproliferative activity against selected tumor cell lines.