Asymmetric Synthesis of 2-Amino Alcohol Derivatives from (S)-α-Amino Aldehydes via Chiral Acetal Templates

Titanium tetrachloride mediated addition of allyltrimethylsilane to chiral acetals derived from (S)-α-amino aldehydes and (+)-(2S,4S)-pentane-2,4-diol gave the anti-2-amino alcohol derivatives with considerably high diastereoselectivity. On the other hand, the same reaction by the use of acetals obtained from (−)-(2R,4R)-pentane-2,4-diol gave the products of opposite stereochemistry series as major products.