Diastereoselective Synthesis of N,N-Dibenzyl-Protected Aminoalkyl Hydroxyethylamines: Key Building Blocks for Hydroxyethylamine-Based BACE1 Inhibitor.

Abstract L-Amino acids were reduced with NaBH4 followed by reacting with benzyl bromide to give N,N-dibenzyl-protected aminoalkyl ethanol 3, which in turn underwent a Swern oxidation, a Johnson–Corey–Chaykovsky reaction, and a nucleophilic reaction to afford N,N-dibenzyl-protected aminoalkyl hydroxyethylamine 6 with a diastereomer ratio 2.5∼2.9:1 of (2R, 3S)-6:(2S, 3S)-6.