8-tert-butyl 3-ethyl 1-oxa-2,8-diazaspiro[4.5]dec-2-ene-3,8-dicarboxylate; 3-ETHYL 8-BOC-1-OXA-2,8-DIAZASPIRO[4.5]DEC-2-ENE-3-CARBOXYLATE; 3-ETHYL 8-BOC-1-OXA-2,8-DIAZASPIRO[4.5]DEC-2-ENE-3-CARBOXYLATE(WXC06048);