103197-51-9Relevant academic research and scientific papers
IMIDAZOLIDINONE DERIVATIVES
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Page/Page column 16, (2008/12/07)
The invention is concerned with novel imidazolidinone derivatives of formula (I): wherein R1 to R11 and X are as defined in the description and in the claims, as well as physiologically acceptable salts thereof. These compounds bind
Synthesis of carbacephems from serine
Folmer, James J.,Acero, Carles,Thai, Dung L.,Rapoport, Henry
, p. 8170 - 8182 (2007/10/03)
Carbacephems have been synthesized from D-serine by two routes involving construction first of the six-membered ring followed by cyclization to give the bicyclic β-lactam. In one route, alkylation of a lactim ether was accomplished with Ni(Acac)2 as a catalyst. The desired R stereochemistry at the carbon corresponding to C-6 of the cephem was obtained by stereospecific hydrogenation of a vinylogous carbamate. The second route involved a stereospecific Michael cyclization to give the same C-6 stereochemistry. Closure of a piperidyl β-amino acid intermediate common to both routes was accomplished using a modified Mukaiyama reagent found to be superior in our system to the traditional reagent. The resulting carbacephem core was stereospecifically substituted at C-7 with an ethyl or amino functionality. The ethylated intermediate was transformed into a stable enol triflate useful for the further elaboration of biologically important carbacephems.
