Combined synthetic CD strategy for the preparation and configurational assignments of model acyclic 1,3-polyols with a 1,2-diol terminal

Acyclic 1,3-polyols or skipped polyols are widely distributed in nature. Particularly skipped 1,3-pobols with a terminal 1,2-diol group are present in numerous antifungal polyene macrolides in various masked forms.' Although over 200 polyene macrolides are known, the planar structures of only about 40 have been determined, while those for which the full stereochemistry has been elucidated is less than ten. No simple method exists for configurational assignments of the 1,3-polyols moieties; moreover, this class of compounds are difficult to crystallize. In order to develop a general chiroptical method for structure determination of acyclic 1,3-polyols, we have combined a divergent synthetic approach with CD to prepare all possible stereoisomers of 1,2,4-triols, 1,2,4,6-tetrols and 1,2,4,6,8-pentols. The current set of reference polyols should be useful for setting up reference CD libraries and for model studies leading to a general method for configurational assignment of acyclic polyols. This strategy can be used to synthesize further extended members of acyclic 1,3-polyols and mixed 1,2/1,3-polyols which can be used for structural investigations of polyene macrolides and related compounds. (C) 1995 Wiley-Liss, Inc.