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

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

8-methyl-4-(2-methylbenzoyl)-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

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

8-methyl-4-(2,4,6-trimethylbenzoyl)-1-oxa-4-azaspiro[4.5]decane-3-carboxylic acid

4-(2,4-dichlorobenzoyl)-8-methyl-1-oxa-4,8-diazaspiro[4.5]decane-3-carboxylic acid

4-[2-(4-methoxyphenyl)acetyl]-8-methyl-1-oxa-4,8-diazaspiro[4.5]decane-3-carboxylic acid

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

4-(2,4-difluorobenzoyl)-8-methyl-1-oxa-4,8-diazaspiro[4.5]decane-3-carboxylic acid

4-(4-chloro-2-fluorobenzoyl)-8-methyl-1-oxa-4,8-diazaspiro[4.5]decane-3-carboxylic acid