151213-75-1Relevant academic research and scientific papers
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.
Chirospecific Synthesis of β-Hydroxy α-Amino Acids
Roemmele, Renee C.,Rapoport, Henry
, p. 1866 - 1875 (2007/10/02)
A variety of β-hydroxy α-amino acids have been synthesized with complete enantiomeric purity from L-serine.These include β-hydroxyglutamic acid, β-hydroxypipecolic acid, β-hydroxylysine, β-hydroxyproline, and β-hydroxymethionine.The syntheses proceed by t
