A General Method for the Synthesis of Enantiopure 1,5-Amino Alcohols

A variety of (R)-phenylglycinol-derived oxazolopiperidone lactams 1–14 were converted to linear-chain enantiopure amino diols 15–26 by reduction with LiNH2BH3 in an unprecedented process involving the simultaneous reductive opening of the oxazolidine and lactam rings. Subsequent removal of the phenylethanol moiety gave enantiopure 5-amino-1-pentanols bearing substituents at the 2-, 3-, 4-, 2,2-, 2,3- 2,4- and 3,4-positions (28–36), which were isolated as their N-Boc derivatives.