178946-64-0Relevant articles and documents
Synthesis of 2-carboxylated aza-ring derivatives through α-monohalogenation/ring-contraction of N-sulfonyl lactams
Sirindil, Fatih,Miaskiewicz, Solène,Kern, Nicolas,Lalaut, Arno,Felten, Anne-Sophie,Weibel, Jean-Marc,Pale, Patrick,Blanc, Aurélien
, p. 5096 - 5106 (2017/07/28)
2-Carboxylated aza-rings have been synthesized in two steps through a highly selective monohalogenation of N-sulfonylated lactams of various ring sizes (from 5- to 8-membered rings) followed by a ring contraction reaction. The selective monohalogenation of N-sulfonyl lactams has been achieved in modest to excellent yields (9 examples, 39–96%) using N-halogenosuccinimides via the in situ generation of trimethylsilyl ketene aminal derivatives. The so-obtained α-halogeno N-sulfonyl lactams were engaged in a ring opening/ring closing reaction in the presence of various alcohols or anilines under basic conditions affording 2-carboxylated aza-rings, such as azetidine, pyrrolidine or piperidine derivatives in high yields (24 examples, 61–99%).
Cephalosporin antibiotics
-
, (2008/06/13)
The present invention relates to compounds of the formula STR1 wherein R1 is an acyl group derived from a carboxylic acid, hydrogen, or an amino protecting group; R2 is hydrogen, hydroxy, lower alkyl-Qp -, cycloalkyl, lowe
