Abstract
As a key intermediate for the synthesis of monobactam analogues, cis-3-benzyloxycarbonyl-amino-4-(2-hydroxyehtyl)-2-azetidinone was synthesized from (4S)-4-methoxycarbonylmethyl-2-azetidinone, and converted into monobactams having a methoxyethyl group at the C-4 position of the β-lactam ring. Among the compounds synthesized, disodium (3S, 4R)-3[2-(2-aminothiazol-4-yl)-(Z)-2-carboxymethoxyiminoacetamido]-4-(2-methoxyethyl)-2-azetidinone-1-sulfonate showed strong activity against a variety of gram-negative bacteria except Pseudomonas aeruginosa. Furthemore, the 4-methoxyethyl derivatives exhibited excellent stabiliy to β-lactamases, and the syntheses of the corresponding trans isomer and 3α-methoxy derivatives are also described.
