| 摘要 |
<p>beta -Lactam compounds of the formula <IMAGE> in which R<1> represents hydrogen or a hydroxyl protective group R<1><a> which is not eliminable under the ring closure conditions and R<2> represents the acyl radical of a weak carboxylic acid, are prepared by reacting a compound of the formula <IMAGE> in which R<1><a> and R<2> have the meanings given under formula I, with chlorosulphonyl isocyanate, reductively eliminating the chlorosulphonyl group from the compound formed, if desired eliminating the hydroxyl protective group R<1><a>, and if desired optionally freeing the compound of the formula I formed from the 3S,4S,1R' diastereomers present.</p> |
