| 摘要 |
<p>Novel thiazolineazetidinone vinyl halides useful in the preparation of certain cephem antibiotics are described. They are of the formula …<CHEM>… wherein X is chloro or bromo; R10 is hydrogen or a carboxylic acid protecting group; and… R5 is… (a) hydrogen, C1-C4 alkyl or halo (C1-C4 alkyl);… (b) a group R6 wherein R6 is phenyl or phenyl substituted by 1 or 2 groups selected from the group consisting of fluoro, chloro, bromo, iodo, nitro, cyano, C1-C4 alkyl, C1-C4 alkoxy, protected hydroxy, carbamyl, trifluoromethyl and methanesulfonamido;… (c) a group of the formula… R6(O)mCH2-… wherein m is I or O and R6 is defined above;… (d) a group of the formula… R6aCH2-… wherein R6a is cyclohexadienyl, 2-furyl, 2-thienyl, or 3-thienyl; or… (e) a group of the formula -COOR wherein R is hydrogen or a carboxylic acid protecting group;… and when R10 is hydrogen the alkali metal salts of the acids represented thereby. …<??>The compounds are prepared from the corresponding enols by action of halogenating compounds derived from triaryl phosphites and chlorine or bromine.</p> |
