Transformations of penicillins. Part V. Reactions of olefin and acetylene derivatives with the sulphenic acid intermediates from penicillin S-oxides
作者:Ian Ager、Derek H. R. Barton、David G. T. Greig、Gino Lucente、Peter G. Sammes、Michael V. Taylor、Graham H. Hewitt、Brian E. Looker、Ann Mowatt、Caroline A. Robson、William G. E. Underwood
DOI:10.1039/p19730001187
日期:——
Norbornadiene, dimethyl acetylenedicarboxylate, and vinyl ethers react with the sulphenic acids produced by heating penicillin S-oxides. Norbornadiene, diketen (4-methyleneoxetan-2-one), and dimethyl acetylenedicarboxylate react by addition, whereas vinyl ethers, such as dihydropyran, react by substitution with loss of water. Methanolysis of the vinyl ether products can be achieved with dilute methanolic
降冰片二烯,乙炔二羧酸二甲酯和乙烯基醚与通过加热青霉素S-氧化物产生的亚硫酸反应。降冰片二烯,二酮(4-亚甲基氧杂环丁-2-酮)和乙炔二甲酸二甲酯通过加成反应,而乙烯基醚(如二氢吡喃)则通过取代反应而失水。可以用稀甲醇盐酸实现乙烯基醚产物的甲醇分解。已经通过吡唑啉途径从乙烯基醚产物中除去了β-内酰胺环的含氮取代基。在将3-羟基penam(22)与丙烯醛一起加热时会发生新的取代反应:置换甲基丙烯醛并形成4-hydroxycepham(25)。据报道这种cepham的一些反应。