SIMPLE AND CONDENSED BETA-LACTAMS .20. REACTION OF SOME 1-(4-METHOXYPHENYL)AZETIDIN-2-ONES WITH CERIUM(IV) AMMONIUM-NITRATE (CAN) - TRAPPING OF THE QUINONE IMINE INTERMEDIATE WITH CHLORIDE AND IODIDE ANIONS

1-(4-Methoxyphenyl)azetidin-2-ones 12 and 13, when treated with cerium(IV) ammonium nitrate (CAN), afford either their N-deprotected derivatives (19, 26) or the chlorinated compounds 22 and 27, respectively, as the main products, depending on whether sodium chloride was present or not. A series of minor products (20, 21, 23-25 and 29, respectively) are formed in addition, 1-(4-Methoxyphenyl)azetidin-2-ones 13 and 14, when treated successively with CAN and sodium iodide, afford the corresponding 1-(4-hydroxyphenyl)azetidin-2-ones 28 and 30, respectively, in good yields. The latter reactions could possibly form the basis for elaboration of a potentially general method for dealkoxy-hydroxylation of N-(2- and 4-alkoxyphenyl)carboxamides. Mechanisms are suggested for the formation of compounds 19 - 30.