Synthesis of (E)-δ-hydroxy-β,γ-dehydroα-amino acids, a new class of vinylglycines by the rearrangement ofβ acetoxyallylglycine derivatives.

The efficient synthesis ofδ-hydroxy-β,γ-dehydroα-amino acids (1) was achieved by the hybrid process, in which the Pd(II)-assisted rear-rangement ofβ-acetoxyallylglycine ester (6) afforded the corresponding (E)-δ-acetoxyvinylglycine derivatives (7) in a moderate yield. The chemo- and stereo-selective hydrolysis of7 was accomplished by the use of microbial lipase (Amano PS) to afford the allylic alcohol (8), which was transformed into1 in two step sequence.