Preparation and Synthetic Applications of (S)- and (R)-N-Boc-N,O-isopropylidene-alpha-methylserinals: Asymmetric Synthesis of (S)- and (R)-2-Amino-2-methylbutanoic Acids (Iva).

This report describes an efficient and convenient large-scale synthesis procedure for (S)- and (R)-N-Boc-alpha-methylserinal acetonides (3 and 4) starting from (R)-2-methylglycidol 5. The application of both of these compounds as valuable chiral building blocks in the asymmetric synthesis of alpha-methylamino acids is also demonstrated by the synthesis of (S)- and (R)-isovalines (Iva) (6 and 7).