Optically active bicyclic oxazolidinylpiperidines 1a, 1b, 1c and 1d, known chiral building blocks for preparing 1-deoxyazasugars, were synthesized in high overall yield from D-serine by a method wherein the titanium(II)-mediated intramolecular nucleophilic acyl substitution and FeCl3-mediated ring enlargement of bicyclic cyclopropanols are the key reactions. (C) 1999 Elsevier Science Ltd. All rights reserved.
Optically active bicyclic oxazolidinylpiperidines 1a, 1b, 1c and 1d, known chiral building blocks for preparing 1-deoxyazasugars, were synthesized in high overall yield from D-serine by a method wherein the titanium(II)-mediated intramolecular nucleophilic acyl substitution and FeCl3-mediated ring enlargement of bicyclic cyclopropanols are the key reactions. (C) 1999 Elsevier Science Ltd. All rights reserved.