POLYSPIRANES .21. REARRANGEMENT CASCADES .15. SYNTHESIS, ABSOLUTE-CONFIGURATION AND SPECIFIC ROTATION OF (+)-MODHEPHENE AND (-)-MODHEPHENE

Although twelve diastereoselective syntheses of(±)‐modhephene have been published, only one enantioselective approach has been reported, in which (—)‐modhephene was assigned a (1R,5S,8R) configuration on the basis of comparable optical rotations. The divergent rotational value measured for a sample taken from Otanthus maritimus was ignored because reliable purity criteria were lacking. This communication proves that all the earlier results with the exception of the absolute configuration must be corrected. (Figure Presented.) Copyright © 1991 by VCH Verlagsgesellschaft mbH, Germany