An asymmetric synthesis route towards (3S,3'S)-(M,M)-(E)-(+)1,1',2,2',3,3',
4,4'-octahydro-3,3',7,7'-tetramethyl-4,4'-biphenanthrylidene was developed
using the Evans procedure as a key step. The absolute configurations of the
title compound and of its parent ketone were determined by CD spectroscopy
and could be correlated with the stereochemical results of the asymmetric
alkylation. Furthermore, a comparison was made with the known (3R,3'R)-(P,P
)- (E)-(-)-1,1',2,2',3,3',4,4'-octahydro-3,3',7,7'-dimethyl-4,4'-biphenanth
rylidene. Finally, the X-ray crystallographic analysis of (3S,3'S)-(M,M)-(E
)-(+)-1,1',2,2',3,3',4,4'-octahydro-3,3',7,7'-tetramethyl-4,4'-biphenanthry
lidene is presented. (C) 2000 Wiley-Liss, Inc.