184871-46-3Relevant articles and documents
Synthesis of 4-oxo-2-azetidineacetic acids by means of radical cyclization of N-vinylic α-bromo amides
Ishibashi, Hiroyuki,Kodama, Kazuya,Kameoka, Chisato,Kawanami, Hirotaka,Ikeda, Masazumi
, p. 13867 - 13880 (1996)
Bu2SnH-mediated radical cyclization of α-bromo amide 8, bearing phenyl and phenylthio substituents at the terminus of the N-vinylic bond, proceeded in a 4-exo-trig manner to give β-lactam 9. Ruthenium tetroxide oxidation of the phenyl group incorporated into the product 9 provided a new synthesis of 4-oxo-2-azetidineacetic acid 13, a useful intermediate for (±)-PS-5. Chiral 4-oxo-2-azetidineacetic acids 23 and 36, key intermediates for the synthesis of (+)-PS-5 and (+)-thienamycin, respectively, were also obtained through the asymmetric radical cyclization of N-vinylic α-bromo amides having chiral auxillaries at the side-chain.
