Enantioselective synthesis of polycyclic ketones by desymmetrisation of bis(phenylsulfonyl)alkenes with chiral alcoholates. Control of the absolute configuration by a simple modification of the chiral auxiliary
S. Cossu et al., Enantioselective synthesis of polycyclic ketones by desymmetrisation of bis(phenylsulfonyl)alkenes with chiral alcoholates. Control of the absolute configuration by a simple modification of the chiral auxiliary, TETRAHEDR L, 40(49), 1999, pp. 8705-8709
Treatment of polycyclic bis(phenylsulfonyl)alkenes with chiral alcoholates,
followed by acidic work-up, affords enantioselectively cx-phenylsulfonyl k
etones. The enantioselectivity is total with monomethylated hydrobenzoin an
d of opposite configuration with respect to that obtained with hydrobenzoin
itself. Thus, starting from a bis(phenylsulfonyl)alkene, it is possible to
obtain either the R or S polycyclic ketone by the use of the same chiral a
uxiliary (hydrobenzoin) and a simple modification (methylation of one of th
e hydroxy functions). (C) 1999 Elsevier Science Ltd. All rights reserved.