77982-91-3Relevant articles and documents
New route to 3-(substituted) methyl 1-oxa- and (1-thia)cephems from 3-exomethylene intermediates via sulfenyl chloride adducts
Aoki,Konoike,Itani,et al.
, p. 2515 - 2526 (2007/10/02)
Addition of methane- and benzenesulfenyl chlorides to 3-exomethylene-1-oxacephams 10 and 14 gave 3β-sulfenyl-3α-chloromethyl adducts 11 and 15. Nucleophilic substitution of the adducts proceeded facilely to afford compounds 18-23, which were converted into Δ3-dervatives 26 and 27 by oxidative elimination. This new route, as illustrated by the sequence 6 → 7 → 8 → 3, has an essential advantage in using the saturated intermediated 7 and 8 with a stabler β-lactam ring which is compatible in nucleophilic substitution, alkaline ester hydrolysis and further manipulations. These synthetic features are well demonstrated by successful synthesis of 1-oxacefamandol 35 and 7β-(2-thienylacetyl-amino)-3-(1-methyl-1H-tetrazol-5-yl)thiomethyl-3-ceph em-4-carboxylic acid (45).
CONVENIENT SYNTHESIS OF 3'-SUBSTITUTED METHYL 7α-METHOXY-1-OXACEPHEMS
Aoki, Tsutomu,Yoshioka, Mitsuru,Kamata, Susumu,Konoike, Toshiro,Haga, Nobuhiro,Nagata, Wataru
, p. 409 - 413 (2007/10/02)
A convenient synthesis of the title compounds 1 is achieved by formation of glycols 3, 12, 13 and 14 or chlorohydrins 6 from epioxazolines having pertinent allylic substituents, followed by stereoselective, intramolecular etherification to 4, 7, 15, 16 an
