RI J, 8diketosulfoxides were reduced with DIBAL to CSzrpS, 8-keto j?-hydroxysulfoxides (de>98%) which can be easily transformed into syn or anti chiral L3diols by known procedures.
Chit-al 1,3-dials are important building blocks in the synthesis of many natural products. Great efforts have been done to develop with success different routes to reduce chit-al B-hydroxyketones into synl or anti 1,3-diols2. However in most of the cases the chiral hydroxylic center present in the Phydroxyketones was obtained from a natural chiral hydroxylated product. We report in this paper a short asymmetric synthesis of B-hydroxyketones monitored by a chiral sulfoxide group. B. Miketosulfoxides were readily prepared in high yields either from &diketones and 0 menthylp-toluenesulfinate, from B-ketoesters and (Z+methylp-tolylsulfoxide or from esters and (RI 1-(1)-tolylsulfinyl) propan-2-one3. It was shown that the Gcarbonyl was totally enolized (scheme 1).
The reduction of these B, Gdiketosulfoxides was carried out with 2 equivalents of DIBAL in THF at -78'C in 15 minutes. As shown in the table I, the chemical yields are high. According to the