专利号:WO-2005100367-A1 优先权日:2004-04-13 标 题 :Intermediates useful in the synthesis of 3-(2-substituted vinyl) cephalosporins 发明人:KUMAR YATENDRA; PRASAD MOHAN; SINGH KAPTAN; PRASAD ASHOK; RICHHARIYA SANTOSH 权利人:RANBAXY LAB LTD; KUMAR YATENDRA; PRASAD MOHAN; SINGH KAPTAN; PRASAD ASHOK; RICHHARIYA SANTOSH 摘要:The present invention relates to crystalline intermediates useful in the synthesis of 3-(2-substituted vinyl) cephalosporins and processes for their preparation. In particular, the present invention relates to crystalline ylides of Formula I, processes for their preparation, and their use as an intermediate in thepreparation of 3-(2-substituted vinyl) cephalosporins.