Asymmetric synthesis of β-lactams. I. The reaction of dimethylketene silyl acetal with (S)-alkylidene(1-arylethyl)amines promoted by titanium tetrachloride

✍ Scribed by Iwao Ojima; Shin-ichi Inaba

• Publisher: Elsevier Science
• Year: 1980
• Tongue: French
• Weight: 227 KB
• Volume: 21
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)71491-2

✦ Synopsis

Asymmetric synthesis of 8-lactams by means of the reaction of dimethylketene silyl acetal with (S)-alkylidenetl-arylethyl)amines in the presence of titanium tetrachloride was studied. The extent of the asymmetric induction was in the range of 44-78% (diastereomeric purity 72-898) and the (S)-configuration was turned to be preferentially induced at the 4 C position of the resulting Blactams. Although a large number of methods for the synthesis of B-lactams have been developed in connection with the naturally occurring 8-lactam antibiotics such as penicillins, cephalosporins ports on the application of recently, Furukawa et al. 3a and nocardicins, 1,2 there have been only a few re-MeOH COOMe COOMe Iol;o Me2C-OH 3 -41.86"(c 1.43, EtOH) Scheme 2.