The regioselective synthesis of optically active 1-diterpenoid acyl-2-acetyl-sn-glycerols is reported. The products are obtained by acylation of 2,3-isopropylidene-sn-glycerol. The key reaction is the deprotection of 1,2-diacyl-3-TBDMS-sn-glycerides by Lewis acid based treatment with PdCl2(CK3CN)(2) in acetone. (C) 1997 Elsevier Science Ltd.
Novel verrucosins from the skin of the Mediterranean nudibranch Doris verrucosa
Nine new diterpenoid acid glycerides (4–12) have been isolated, together with the previously reported 13 and 14, from the skin extract of the Mediterranean nudibranch Dorisverrucosa. The structure and the relative stereochemistry of the new metabolites were established by interpretation of spectral data. Absolute stereochemistry of the diterpenoid part was suggested by biogenetic considerations as