Y. Ueno, K. Tadano, S. Ogawa
Jul 1, 1989
Citations
0
Influential Citations
31
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
Enantiospecific total synthesis of (+)-altholactone [(+)-goniothalenol] (1), a novel tetrahydrofuropyran-5-one possessing significant cytotoxicity against several tumor cell lines, has been achieved by using L-arabinose as the redundant starting material. The pivotal tetrahydrofuran formation was realized by treatment of the diastereomeric mixture of (2S,3R)-4,5-epoxy-5-phenyl-1,2,3-pentanetriol 1,3-benzylidene acetals 8 and 8′ with silica gel. Simultaneous stereochemical inversion at C-4 and C-5 of the major cyclization product, O,O′-benzylidene derivative of (2S,3R,4S,5S)-2-(hydroxymethyl)-5-phenyltetrahydrofuran-3,4-diol (11), to the 2S,3R,4R,5R diastereomer 10 was achieved by hydroboration of (2S,3S)-3-hydroxy-2-(hydroxymethyl)-5-phenyl-2,3-dihydrofuran O,O′-benzylidene derivative (18) which derived from 11. Pfitzner-Moffatt oxidation of 10 followed by NaBH4 reduction gave the 2S,3R,4S,5R diastereomer 20 exclusively. Displacement of the triflate group in (2S,3R,4S,5S)-2-(hydroxymethyl)-5-phenyl-4-[(tr...