Absolute stereostructure of callystatin A, a potent cytotoxic polyketide from the marine sponge, Callyspongia truncata

Article abstract of DOI:10.1016/S0040-4039(97)01194-5

The unidentified configurations at C₅ and C₁₀ incallystatin A (1), a potent cytotoxic polyketide from the marine sponge Callyspongia truncata, were determined to be R,R by comparing the circular dichroism spectrum of 1 with those of two model compounds 2 and 3. Compounds 2 and 3 were synthesized by using E-selective Wittig olefination at the C₆-C₇ position as a key reaction.