摘要:
The synthesis of optically active Hagemann's esters was investigated. The starting materials in this approach were enamino esters (R,Z)-8, prepared through the condensation of keto ester 6 with (R)-1-phenylethylamine 7. Michael addition reaction of the enamino esters (R,Z)-8 with methyl vinyl ketone gave the expected adducts 10 with good e.e.s of 93-96%. Subsequent annulation of the adducts furnished optically active Hagemann's esters. (C) 2001 Elsevier Science ltd. All rights reserved.