Synthesis of enantiomerically pure α-amino acids via chemo-and diastereoselective alkylation of (5S)-5-phenyl-5, 6-dihydro-2H-1, 4-oxazin-2-one

LM Harwood, SNG Tyler, AS Anslow, ID MacGilp…

Index: Harwood, Laurence M.; Tyler, Simon N. G.; Anslow, A. Susan; MacGilp, Iain D.; Drew, Michael G. B. Tetrahedron Asymmetry, 1997 , vol. 8, # 24 p. 4007 - 4010

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Citation Number: 21

Abstract

General two-step procedure for synthesis of adducts 3: (5S)-5-phenyl-3,4,5,6-tetrahydro-2H-1 ,4-oxazin-2-one1 (0.71 mmol) was prepared as described previously 4 and the crude product immediately dissolved in anhydrous tetrahydrofuran (6 mL) under nitrogen and the solution cooled to −40°C. Boron trifluoride etherate (0.10 mL, 0.79 mmol, 1.1 eq.) was added in a single portion and the reaction mixture stirred at −40°C for 2 h, whereupon the requisite Grignard ...