| 摘要 |
<p>The present invention relates the removal of t-butyldimethylsilyl protecting groups in the preparation of penems which are useful antibiotics. The invention provides a process for preparing a compound of the formula I: <IMAGE> I wherein R is a free or protected hydroxy or amino group or an alkoxy, acyloxy or an optionally substituted carbamoyloxy group, and R1 is selected from: a) hydrogen; b) a C2-C4 alkenyl group; c) a p-NO2 benzyl group; d) a linear or branched alkanoyloxy C1-C2 alkyl group; and e) (2-oxo-1,3-dioxolen-4-yl)methyl optionally substituted by C1-C4 alkyl at the 5-position or a pharmaceutically acceptable salt thereof, which process comprises reacting a compound of the formula II: <IMAGE> II</p> |
