G. Burtin et al., Stereoselective synthesis of beta-substituted aspartic acids via tetrahydro-1,3-oxazin-6-ones, TETRAHEDR L, 40(22), 1999, pp. 4275-4278
Oxazinones have been synthesised and used as chiral templates in the synthe
sis of beta-substituted aspartic acids. Use of a Brebereck's reagant/Grigna
rd/hydrogenation strategy gave cis-oxazinones with complete stereoselectivi
ty, whereas an alkylation strategy, although trans-selective, gave mixtures
of isomers. The oxazinones could be convened to beta-substituted aspartic
acids and to regioselectively protected beta-substituted aspartic acids wit
hout loss of stereochemistry at either centre. (C) 1999 Elsevier Science Lt
d. All rights reserved.