4-(4-tert-butylbenzoyl)-1-oxa-4-azaspiro[4.5]decane-3-carboxylic acid

4-(3,5-dichlorobenzoyl)-1-oxa-4-azaspiro[4.5]decane-3-carboxylic acid

4-(4-chloro-2-fluorobenzoyl)-1-oxa-4-azaspiro[4.5]decane-3-carboxylic acid

4-(4-methoxybenzoyl)-8-methyl-1-oxa-4-azaspiro[4.5]decane-3-carboxylic acid

8-methyl-4-(thiophene-2-carbonyl)-1-oxa-4-azaspiro[4.5]decane-3-carboxylic acid

8-methyl-4-(3-phenylpropanoyl)-1-oxa-4-azaspiro[4.5]decane-3-carboxylic acid

4-(3-bromobenzoyl)-8-methyl-1-oxa-4-azaspiro[4.5]decane-3-carboxylic acid

4-(2-bromobenzoyl)-8-methyl-1-oxa-4-azaspiro[4.5]decane-3-carboxylic acid

4-[4-(dimethylamino)benzoyl]-8-methyl-1-oxa-4-azaspiro[4.5]decane-3-carboxylic acid

4-(3,5-difluorobenzoyl)-8-methyl-1-oxa-4-azaspiro[4.5]decane-3-carboxylic acid

4-(4-fluorobenzoyl)-8-methyl-1-oxa-4,8-diazaspiro[4.5]decane-3-carboxylic acid