Process for the separation of 3-formyl-cephem derivatives

摘要

Prodn. of 3-formyl cephem cpds. of formula (I) comprises oxidising a 3-hydroxymethyl cpd. of formula (II) with an inorganic hypohalite or halite in the presence of a catalyst: R1, R2 = H or amino-protecting gps.; R3 = a carboxy-protecting gp. The catalyst is a nitroxyl radical or related cpd. of formula (III): R4 = lower alkyl; R5 = R6 = H or lower alkoxy, or one is H and the other is OH, lower alkoxy, alkanoyloxy, aroyloxy or alkanoylamino; or R5+R6 = OCH2CH2O, OCHR7CH2O or OCH2CR7R7CH2O; R7 = lower alkyl; Y = N<+)<=O).X<->, N-OH or N-O<.>; X = an anion.