Stereoselective synthesis of β-substituted aspartic acids via tetrahydro-1,3-oxazin-6-ones

Article abstract of DOI:10.1016/S0040-4039(99)00705-4

Oxazinones have been synthesised and used as chiral templates in the synthesis of β-substituted aspartic acids. Use of a Bredereck's reagent/Grignard/hydrogenation strategy gave cis-oxazinones with complete stereoselectivity, whereas an alkylation strategy, although trans-selective, gave mixtures of isomers. The oxazinones could be converted to β-substituted aspartic acids and to regioselectively protected β-substituted aspartic acids without loss of stereochemistry at either centre.