Chelation controlled aldol additions of the enolsilane derived from tert-butyl thioacetate : a stereosetective approach to 1β-methylthienamycin
作者:Cesare Gennari、Pier Giorgio Cozzi
DOI:10.1016/s0040-4020(01)81455-1
日期:1988.1
The tert-butyldimethylenolsilane derived from tert-butyl thioacetate is a useful reagent for highly stereoselective chelation-controlled additions to chiral α-alkoxy and α-methyl-β-alkoxy aldehydes where the corresponding acetate fails. The aldol product deriving from the TiCl4 mediated addition to α-methyl-β-alkoxy aldehyde 5 was elaborated In high yield to give the bicyclic β-lactam 11, an Intermediate
Synthetic carbapenem antibiotics II. Stereoisomers of 7-hydroxyethyl-2,2,5-trimethyl-3-oxa-1-azabicyclo[4.2.O]octan-8-one
作者:David H. Shih、Judith A. Fayter、L.D. Cama、Burton G. Christensen、Jordan Hirshfield
DOI:10.1016/s0040-4039(00)89153-4
日期:1985.1
The titled compounds are key synthetic intermediates in the structure-activity relationship studies of novel 1-methyl carbapenem antibiotics. Preparation and structuraldetermination of these stereoisomers by x-ray crystallography and proton NMRspectroscopy are reported.