Studies on lactams. Part 65. N-Unsubstituted .beta.-lactams from .beta.-hydroxy-.alpha.-amino acids. Facile preparation of intermediates for isocephalosporins
Enantiospecific synthesis of β-lactams via cycloaddition
作者:Ajay K. Bose、M.S. Manhas、J.M. van der Veen、S.S. Bari、D.R. Wagle、V.R. Hegde、Lalitha Krishnan
DOI:10.1016/s0040-4039(00)98458-2
日期:1985.1
substituted cis-β-lactams can be achieved by the annelation of Schiff bases from optically active ketal aldehydes derived from D-threonine. Similar annelation of Schiff bases from the triphenylsilyl ether of D-threonine ester and cinnamaldehyde leads to cis-β-lactams with high diastereofacialselectivity.
Studies on lactams. Part 65. N-Unsubstituted .beta.-lactams from .beta.-hydroxy-.alpha.-amino acids. Facile preparation of intermediates for isocephalosporins
作者:Ajay K. Bose、M. S. Manhas、J. E. Vincent、K. Gala、I. F. Fernandez
DOI:10.1021/jo00142a015
日期:1982.10
Stereoregulated synthesis of β-lactams from schiff bases derived from threonine esters
作者:Ajay K. Bose、Maghar S. Manhas、James M. van der Veen、Shamsher S. Bari、Dilip R. Wagle
DOI:10.1016/s0040-4020(01)81577-5
日期:1992.6
3-substituted-2-azetidinones has been prepared by the annelation of Schiff bases derivedfrom cinnamaldehyde and D-threonine esters and their absolute configuration determined. When the β-hydroxyl group of threonine is unprotected, both enantiomeric forms of N-unsubstituted 3,4-disubstituted-2-azetidinones can be prepared from a single β-lactam-forming reaction. On the other hand, by converting the hydroxyl