are not both 1 y is selected from the group consisting of alkyl halo e g fluoro chloro etc nitro amino thiol hydroxy alkyloxy alkylcarboxy halo substituted alkyl wherein said alkyl radical comprises from one to six carbon atoms etc and n is 0 or an integer of from 1 to 3 and r 3 is u2550 o u2014 oh or u2014 o co r 6 wherein r 6 is as defined above or a pharmaceutically acceptable salt thereof wherein hatched lines indicate u03b1 configuration solid triangles are used to indicate u03b2 configuration in another embodiment y is 1 and x is 0 and r 1 r 2 and r 3 are hydroxy one exemplary compound is cyclopentane n ethyl heptanamide 5 cis 2 3 u03b1 hydroxy 5 phenyl 1 trans pentenyl 3 5 dihy droxy 1 u03b1 2 u03b2 3 u03b1 5 u03b1 also known as bimatoprost and sold under the name of lumigan u00ae by allergan inc california usa this compound has the following structure the synthesis of the above compounds has been disclosed in u s pat no 5 607 978 which is incorporated by reference in its entirety effective amounts of the active compounds can be determined by one of ordinary skill in the art but will vary depending on the compound employed frequency of application and desired result the compound will generally range from about 1 u00d7 1 0 7 to about 50 w w of the composition in.