Abstract-Aliphatic ketones were reduced to the corresponding secondary alcohols by using anti-1,3-diol and a catalytic amount of 2,4-dinitrobenzenesulfonic acid (DNBSA) in benzene at reflux. Addition of 1-octanethiol in that media improved the efficiency of the reduction. Asymmetric reduction of aliphatic ketones was performed by using chiral anti-pentane-2,4-diol, and highly asymmetric induction (up to >99% ee) was observed in the reduction of tert-alkyl ketones. Asymmetric reduction of acyl silanes using chiral antipentane-2,4-diol and DNBSA proceeded efficiently in the absence of octanethiol and the corresponding -silyl alcohols were obtained in high yields with high ees.

A wide range of linear and cyclic ketones is reduced to the corresponding alcohols with moderate yields and good to excellent enantioselectivities. The addition of octanethiol is required in this case. Asymmetric reduction is applied to a variety of acyl silanes. The reaction proceeds effectively without thiol and is sensitive to the steric effects [cf. (VIIIc,f,g)]. -(MATSUO*, J.-I.; HATTORI, Y.; HASHIZUME, M.; ISHIBASHI, H.; Tetrahedron 66 (2010) 32, 6062-6069, http://dx.