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

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

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

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

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

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

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

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

8-ethyl-4-(furan-2-carbonyl)-1-oxa-4,8-diazaspiro[4.5]decane-3-carboxylic acid