Hydroxy-substd. azetidinone derivs. of formula (I) and their salts are new. Ar1,Ar2 = aryl (opt. substd. by 1-5 gps. R4) Ar3 = aryl (opt. substd. by 1-5 gps. R5) X, Y, Z = CH2, CH(1-6C alkyl) or C(di(1-6C alkyl) R, R2 = OR6, OCOR6, OCOOR9 or OCONR6R7 R1, R3 = H, 1-6C alkyl or aryl q, r = 0 or 1 m, n, p = 0-4, provided that i) at least one of q and r is 1, and the sum of m, n q and r is 1-6, and ii) when p is 0 and r is 1, the sum of m, q and n is 1-5 R4 = 1-6C alkyl, OR6, OCOR6, OCOR9, O(CH2)sOR6, OCONR6R7, NR6R7, NR6COR7, NR6COOR9, NR9, NR6CONR7R8, NR6CONR7R8, NR6SO2R9, COOR6, CONR6R7, COR6, SO2NR6R7, S(O)tR9, O(CH2)uCOOR6, O(CH2)uCONR6R7, lower alkylCOOR6, CH=CH-COOR6, CF3, CN, NO2 or halogen R5 = OR6, OCOR6, O(CO)R9, O(CH2)vOR6, -O(CO)NR6R7, NR6R7, NR6COR7, NR6COOR9, NR6COOR9, NR6CONR7R8, NR6SO2R9, COOR6, CONR6R7, COR6, SO2NR6R7, S(O)tR9, -O(CH2)uCOOR6, O(CH2)uCONR6R7, lower alkylCOOR6 or -CH=CH-COOR6 s = 1-5 t = 0-2 u = 1-10 v = 1-5 R6, R7, R8 = H, 1-6C alkyl (opt.substd. with aryl) or aryl and R9 = 1-6C alkyl (opt. substd. with aryl) or aryl.
