Phosphine-Catalyzed [3+2] Cycloadditions of 2-Phenyl-4-Arylidene-5(4H)-Oxazolones with Allenoate: A Concise Synthesis of Aspartic Acid Analogues.

A Ph3P-catalyzed [3+2] cycloaddition of 2<italic>-</italic>phenyl-4-arylidene-5(4<italic>H</italic>)-oxazolones with benzyl 2,3-butadienoate has been developed for the efficient synthesis of structurally diverse and conformationally constrained aspartic acid analogues. [ABSTRACT FROM AUTHOR]