Problems to be solved are to provide novellow-molecular compounds which exhibit calcium receptorantagonist activity, and which are highly safe and orallyadministrable. As a means for solving the problems,compounds having the Formula (I) or pharmaceuticallyacceptable salts thereof are provided.(see formula I)[in the formula, the substituent groups are defined asfollows. R1 and R2a, R2b: a hydrogen atom, etc. R3: amethyl group, an ethyl group, etc. Z: a carboxy group, etc.Ar: a phenyl group, etc. A: a single bond, etc. B: asingle bond, etc. n: 0 or 1. m: an integer of 0 to 6.]
