DIASTEREOSELECTIVE ADDITION OF ORGANOMETALLICS TO ALPHA-KETO ESTERS BEARING CHIRO-INOSITOL DERIVATIVES AS CHIRAL AUXILIARIES

The nucleophilic addition of organometallics to alpha-keto esters derived from (1L)-1,2:5,6-di-O-cyclohexylidene-3-t-butyldimethylsilyl-chiro-inositol afforded the corresponding alpha-hydroxy esters of high diastereomeric excess (up to 98% de). Grignard reagents attacked from re-face, while organolithium reagents preferred si-face attack.