Compounds are provided having the formula (I) 1 wherein: n is 0, 1 or 2; m is 0, 1 or 2; the sum of n+m less then or equal to 2; the dashed bonds forming a cyclopropyl ring can only be present when Y is CH; X is H or CN; Y is CH, CH.sub.2, CHF, CF.sub.2, O, S, SO, or SO.sub.2; and A is adamantyl. Further provided are methods of using such compounds for the treatment of diabetes and related diseases, and to pharmaceutical compositions containing such compounds.