1-Oxa-3,8-diazaspiro(4.5)decan-2-one, 3-butyl-8-(2-(4-fluorophenylethyl)-4-methylene- 134069-90-2 3-Butyl-8-(2-(4-fluorophenyl)ethyl)-4-methylene-1-oxa-3,8-diazaspiro(4.5)decan-2-one