Asymmetric ozone oxidation of silylalkenes using a C₂- symmetrical dialkoxysilyl group as a chiral auxiliary

Ozone oxidation of silyl-substituted alkenes, namely silylalkenes, proceeds in an addition-type manner to afford α-silylperoxy carbonyl compounds in good to excellent yields, without the formation of normal ozonolysis products. Herein the ozone oxidation of chiral alkenylsilanes prepared from alkynes and a newly designed chiral hydrosilane is reported. The reaction affords silylperoxides with high diastereoselectivity (up to 94 % d.r.). The silylperoxides are convertible into enantioenriched chiral acyloins in a stereospecific manner. Putting ozone to work: Ozone oxidation of chiral alkenylsilanes prepared from alkynes and a newly designed chiral hydrosilane affords silylperoxides with high diastereoselectivity (up to 94 % d.r.; see scheme). The silylperoxides are convertible into enantioenriched chiral acyloins in a stereospecific manner.