655252-87-2Relevant academic research and scientific papers
Medium ring ethers via [1,2]-shift of acetal-derived oxonium ylides
Tester, Richland W.,West
, p. 4631 - 4634 (1998)
Cyclic acetals and ketals with pendant diazoketones rearranged to O- bridged medium ring in the presence of catalytic Rh2(OAc)4 or Cu(hfacac)2. This process proceeds via fused bicyclic oxonium ylides which undergo [1,2]- shift reactions. The observation of efficient migration by alkyl substituted carbons lacking any conjugating groups is especially notable. Overall, this chemistry furnishes functionalized medium ring ethers in a few steps from simple precursors.
5-Hydroxy[1,2]oxazinan-3-ones as potential carbapenem and D-ala-D-ala surrogates
Wolfe, Saul,Akuche, Christiana,Ro, Stephen,Wilson, Marie-Claire,Kim, Chan-Kyung,Shi, Zheng
, p. 915 - 936 (2007/10/03)
The title compounds are amino acids whose nitrogen atom is enclosed in a six-membered cyclic hydroxamate bearing a C5-hydroxyl group. They belong to a proposed new family of antibacterial agents targeted to the penicillin receptor. The glycine and alanine members of the family have been synthesized, as racemates, in seven steps from the four-carbon synthon diketene and the tert-butyl esters of N-hydroxyglycine and N-hydroxyalanine. Numerous alternatives to diketene have also been examined, but these lead mainly to five-membered cyclic hydroxamates. The theoretical considerations that have led to this synthetic programme are discussed in some detail. They include analysis of the structures of natural and unnatural penicillin surrogates, analysis of the penicillin pharmacophore, and a treatment of the chemical reaction with which penicillin blocks bacterial cell wall synthesis. The glycine derivative exhibits marginal but real activity vs. Micrococcus luteus. The alanine derivative, which more closely resembles D-ala-D-ala, is fifty times more active. Two five-membered structural isomers of the glycine derivative are inactive.
