The asymmetric borohydride reduction of prochiral ketones by different kinds of chiral phase transfer catalysts under the condition of S L phase transfer catalysis was explored and the influence of different solvents, temperatures and catalysts to the reaction was investigated.

Asymmetric borane reduction of prochiral ketones is a good process to the synthesis of enantiomerically enriched secondary alcohols.

Dioxiranes,which could be generated in situ from chiral ketones and potassium peroxomonosulfate(KHSO_5),have been shown to be remarkably promising oxidation reagents for asymmetric epoxidation of cis-olefins,trans-olefins,trisubstituted olefins and terminal olefins.

Using 10 as the catalyst, six prochiral ketones were reduced enantioselectively with borane and the results were compared with those with 1,1- diphenylprolinol as catalys.

Two groups of catalysts,(S)-diphenylprolinol(1) and(2S)-diphenylhydroxymethyl-(4S)-phenoxy-pyrrolidine(2),(R)-2-amino-1,1-diphenyl-3-(2-naphthyl)-1-propanol(3) and(R)-1-(1′-amino-2′-naphthylethyl)-cyclopentanol(4),were prepared and used in the enantioselective reduction of six prochiral ketones with borane.

Asymmetric reduction of prochiral ketones using oxazaborolidines has become one of the standard tools for the synthetic chemist, allowing access to enantiomerically enriched secondary alcohols with excellent enantiomeric excess that may seve as the chiral ligands for enantionselectivity synthesis and highly useful intermediates in the sy.

Chiral ketone 4 derived from D-(-)-fructose was obtained by four steps reaction including protection with acetone, oxidation, deprotection selectively and trifluroacetylation.

Dioxiranes, which could be generated in situ from chiral ketone and potassium peroxomonosulfate (Oxone), are remarkably effective oxidation reagents for asymmetric epoxidation of olefins.

The reactions includes dimerization of the a-methylstyrene (AMS), deprotection of acetals(ketals) and asymmetric epoxidation catalyzed by chiral ketones.