Lipase-Catalyzed Enantioselective Acetylation of Prochiral N-Cbz-2-Alkyl-2-Amino-1,3-Propanediols and Enantiodivergent Synthesis of α-Benzylserine

Enzymatic acetylation of several varieties of N-Cbz-2-alkyl-2-amino-1,3-propanediols 3a-d with immobilized lipoprotein lipase from Pseudomonas sp. afforded N-Cbz-3-acetoxy-2-alkyl-2-amino-1-propanols 4a-d in up to 98% ee. A facile synthesis of (R)- and (S)-a-benzylserines [(R)- and (S)-8a] was achieved by enantiodivergent conversion of chiral N-Cbz-3-acetoxy-2-amino-2-benzyl-1-propanol (R)-4a.