作者:János Pitlik、Tamás E. Gunda、István Miskolczi
DOI:10.1002/jhet.5570270521
日期:1990.7
undergoes a regio- and stereoselective 1,3-dipolar cycloaddition with diazomethane to give novel cephalosporins, a 3-pyrazolinocephem (4) and a double adduct (5). The vinylcephalosporin sulphoxide (2) gives only the pyrazolinocephem (7). In the reaction with diphenyldiazomethane upon heating the initially formed pyrazolines decompose and cyclopropylcephalosporin (9) formation takes place. The determination
乙烯基头孢菌素(1)与重氮甲烷进行区域选择性和立体选择性的1,3偶极环加成反应,得到新的头孢菌素,3-吡唑啉酮ephem (4)和双加合物(5)。乙烯基头孢菌素亚砜(2)仅产生吡唑啉olin(7)。在加热时与二苯基重氮甲烷的反应中,最初形成的吡唑啉分解,并发生环丙基头孢菌素(9)的形成。还描述了这些化合物的结构和立体化学的测定。