Asymmetric syntheses of all four stereoisomers of 2,3-methanomethionine
作者:Kevin Burgess、Kwok Kan Ho
DOI:10.1021/jo00048a028
日期:1992.10
Asymmetric syntheses of all four stereoisomers of 2,3-methanomethionine ((Z)- and (E)-cyclo-Met) are described. The source of chirality in these reactions is the trifluoromethylsulfonate ester 1b which reacts with di-tert-butyl malonate via direct displacement of trifluoromethylsulfonate followed by lactonization to give 1-(tert-butoxycarbonyl)-2-oxo-3-oxabicyclo[3.1.0]hexane (2). Conversion of compound 2 into (Z)-cyclo-Met can be achieved via ring opening of the lactone, Hoffmann rearrangement, mesylation, and displacement with thiomethoxide. A route to (E)-cyclo-Met was developed using a lipase to effect a critical ester hydrolysis.
KOSKINEN, ARI M. P.;MUNOZ, LUIS, J. CHEM. SOC. CHEM. COMMUN.,(1990) N9, C. 1373-1374
作者:KOSKINEN, ARI M. P.、MUNOZ, LUIS
DOI:——
日期:——
1-Amino-2-oxo-3-oxabicyclo[3.1.0]hexane (2,3-methanohomoserine lactone), a conformationally constrained amino acid
作者:Ari M. P. Koskinen、Luis Muñoz
DOI:10.1039/c39900001373
日期:——
A rapid high yielding synthesis of N-t-butoxycarbonyl-1-amino-2-oxo-3-oxabicyclo[3.1.0]hexane is described; the synthesis relies on an intramolecular carbenoid reaction of an appropriate malonate derivative followed by Curtius degradation to give the unprotected amino group.