3479-47-8Relevant articles and documents
Synthesis of polyaspartic acid.
FRANKEL,BERGER
, p. 213 - 213 (1949)
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Tetrahydro-1,3-oxazin-6-ones as templates for the stereoselective synthesis of β-substituted L-aspartic acids
Burtin, Guillaume,Corringer, Pierre-Jean,Young, Douglas W.
, p. 3451 - 3459 (2007/10/03)
Protected (4S)-4-carboxytetrahydro-1,3-oxazin-6-ones have been synthesised either by Baeyer-Villiger reaction on a 4-ketoproline derivative or, more directly, from an aspartate derivative. Two strategies have been used to develop these compounds as chiral templates in the synthesis of β-substituted aspartic acids. In the first, formation of an enaminone using Bredereck's reagent, followed by reaction with a Grignard reagent gave a series of alkylidene derivatives which could be reduced from the less hindered side by heterogeneous catalytic hydrogenation to give cis-oxazinones in a completety stereoselective manner. Alternatively, an alkylation strategy, although trans-selective, gave mixtures of isomers. The oxazinones were converted to β-substituted aspartic acids and to regioselectively protected β-substituted aspartic acids without loss of stereochemistry ar either centre.
Cleavage of Esters under Nearly Neutral Conditions at High Pressure. Chemo- and Regioselective Hydrolysis in Organic Solvents
Yamamoto, Yoshinori,Furuta, Toshiaki,Matsuo, Jiro,Kurata, Tetsuro
, p. 5737 - 5738 (2007/10/02)
Hydrolysis of esters proceeded at room temperature under high pressure in the presence of iPr2NEt or N-methylmorpholine using CH3CN-H2O (60:1) as the solvent.This very mild procedure enables the smooth hydrolysis of biologically important compounds such as amino esters, aliphatic unsaturated fatty esters, and β-hydroxy esters; no racemization, no isomerization, and no side reactions take place.