| 摘要 |
<p>The invention provides a novel process for opening the ring of 2-R-6-(1'-R1-oxycarbonyl-2'-methyl-prop-1'-enyl)-1-oxa-3,6-diaza-4?,5?-bicyclo ¢3,2,0!hept-2-en-7-one by treatment with a sulfonic acid salt thereby forming R1 2(2'?-R-oxy-3'?-amino-4'-oxo)azetidinyl-3-methyl-2-butenoate sulfonic acid salts which can provide oxapenicillins by two different routes depending on the substituent desired on the carboxamido group of the 1-oxapenicillins. In the alternate processes, new intermediates are also provided.</p> |
