ASYMMETRIC-SYNTHESIS OF DISUBSTITUTED C-SILYLATED HOMOALLYLIC ALCOHOLS FROM LITHIATED ALLYLIC AND VINYLIC SULFOXIMINES

Lithiation, titanation and hydroxyalkylation of allylic N-methyl sulfoximines 1-4 gave with greater than or equal to 95% de the anti-Z-configurated homoallylic alcohols 5-9. Lithiation of 6b and 8b with MeLi readily produced the lithiated vinylic sulfoximines (Z)-12 and (Z)-13, respectively. Ni-catalyzed substitution of (Z)-12 and (Z)-13 with PhLi and 1,5-silyl migration yielded with greater than or equal to 98% de the disubstituted C-silylated homoallylic alcohols (Z)-14 and (Z)-15,respectively. (Z)-15 thus obtained from (Z)-13 had an ee-value of greater than or equal to 98%.