Asymmetric synthesis of (1'R,3R,4R)-4-acetoxy-3-[1'-((tert-butyldimethylsilyl)oxy)ethyl]-2-azetidinone and other 3-(1'-hydroxyethyl)-2-azetidinones from (S)-(+)-ethyl 3-hydroxybutanoate: formal total synthesis of (+)-thienamycin
作者:Gunda I. Georg、Joydeep Kant、Harpal S. Gill
DOI:10.1021/ja00238a023
日期:1987.2
Stereoselective synthesis of .beta.-lactams by condensation of titanium enolates of 2-pyridyl thioesters with imines
作者:Rita Annunziata、Mauro Cinquini、Franco Cozzi、Pier Giorgio Cozzi
DOI:10.1021/jo00041a019
日期:1992.7
A mild and versatile one-pot synthesis of beta-lactams has been performed by condensation of the easily generated titantium enolates of 2-pyridyl thioesters with imines employing chiral reaction partners. Both imines obtained from enantiomerically pure alkoxy aldehydes and the enolate derived from 3-hydroxybutyrate showed high diastereofacial preferences, efficiently transferring the stereochemical information to the stereocenters of the azetidinone ring. Advanced precursors of (+)-PS-5, (+)-PS-6, thienamycin, and 1-beta-methylthienamycin were prepared to illustrate the potential of this method. A H-1-NMR study of the enolization process and a tentative rationalization of the stereochemical results are presented.
GALLUCCI, JUDITH C.;HA, DEOK-CHAN;HART, DAVID J., TETRAHEDRON, 45,(1989) N, C. 1283-1292
作者:GALLUCCI, JUDITH C.、HA, DEOK-CHAN、HART, DAVID J.
DOI:——
日期:——
Anodic N-dearylation of 2-azetidinones
作者:Edward G. Corley、Sandor Karady、Newton L. Abramson、Dean Ellison、Leonard M. Weinstock