ABSOLUTE STEREOSTRUCTURE AND TOTAL SYNTHESIS OF LEPTOMYCIN-B

The absolute stereostructure of leptomycin B, an antitumor antibiotic and inhibitor of nuclear protein export, was firstly presumed as 1 hav ing 4S, 5R, 10R, 16R, 18S, 19R, 20S on the basis of NMR comparison wit h callystatin A (2) and then 1 was asymmetrically synthesized. The syn thesized leptomycin B (I) was found identical with the authentic sampl e in HPLC and CD comparison as well as in other respects. This structu ral elucidation of the absolute stereostructure and total synthesis ar e the first example;among the leptomycin family as Streptomyces metabo lites. (C) 1998 Elsevier Science Ltd. All rights reserved.