This invention provides a compound of the following formula:and the pharmaceutically acceptable salts thereof, wherein L is
oxygen or
sulfur; Y is a direct bond or C1-4 alkylidene; Q is C1-6
alkyl, C3-7 cycloalkyl, phenyl, naphthyl, heteroaryl or the like; R1 is
hydrogen, C1-6
alkyl or the like; R2 is
hydrogen, C1-4
alkyl, C(O)R5 wherein R5 is C1-22 alkyl or C2-22 alkenyl, halosubstituted C1-8 alkyl, halosubstituted C2-8alkenyl, -Y-C3-7 cycloalkyl, -Y-C3-7 cycloalkenyl, phenyl, naphthyl, heteroaryl or the like; X is halo, C1-4 alkyl, hydroxy, C1-4 alkoxy or the like; and n is 0, 1, 2 or 3, with the proviso that a group of formula -Y-Q is not methyl or ethyl when X is
hydrogen; L is
oxygen; R1 is hydrogen; and R2 is acetyl.This invention also provides a pharmaceutical composition useful for the treatment of a medical condition in which prostaglandins are implicated as pathogens.