1. A compound having structural Formula Ia: and pharmaceutically acceptable salts thereof, wherein: Z is R is where *** is a carbonyl carbon attachment, and ** is a tetrazolyl ring attachment in Formula Ia； X is O, NH or S； m is an integer selected from 1 or 2； n is an integer selected from 1 or 2； each X, X, and X are independently selected from C (R) or N, provided that at least one of X, X, and X must be N, and at most two of X, X, and X are N； R is —CN； R is —H or —Calkyl； R is —H, —F, —Cl, —Calkyl, —Cycloalk sludge or —OCalkyl； R is —H, —F, —Cl, —CN, —Calkyl, —Cycloalkyl or —OCalkyl； R is —F, —Cl, —CN, —Calkyl, —Cycloalkyl, —OCalkyl or N-tetrazolyl； or R and R are combined with the carbon atoms in the phenyl ring to which they are attached to form: wherein R is —H or —Ci-alkyl； R is -H, -Cl, -F, -CN, -Ci-alkyl, -C-cycloalkyl or -OC-alkyl； provided that when R and R are not connected, then one and only one of R, R or R is —CN； R is —H or —Calkyl； and R is -H, -F, -Cl or -Calkyl. 2. A compound according to claim 1, having structural Formula I: and its pharmaceutically acceptable salts, where: X is O, NH or S； R is where *** is a carbonyl carbon and ** is a tetrazolyl ring in Formula I ； m is an integer selected from 1 or 2； n is an integer selected from 1 or 2； each X, X, and X are independently selected from C (R) or N, provided that at least one of X, X, and X must be N, and at most two of X, X and X are N； R is —H, —F, —Cl, —Calkyl, —Cycloalkyl or —OCalkyl； R is —H, —F, —Cl, —CN, —Calk scrap -Ctsikloalkilom or -OCalkilom； Ryavlyaetsya -F, -Cl, -CN, -Calkilom, -Ctsiklo1. Соединение, имеющее структурную Формулу Ia:и его фармацевтически приемлемые соли, где:Z являетсяRявляется,где *** обозначает присоединение к карбонильному углероду, и ** обозначает присоединение к тетразолильному кольцу в Формуле Ia；X является O, NH или S；m является целым числом, выбранным из 1 или 2；n является целым числом, выбранным из 1 или 2；каждый X, Xи Xнезависимо выбран из C(R) или N, пр
