1,4-Dioxa-8-azaspiro[4.5]decane4-Piperidone ethylene ketal 98%4-Piperidone ethylene ketal1,4-DIOXA-8-AZASPIRO-(4.5)DECANE1,4-二叠氮-8-壬烯1,4-Dioxa-8-azaspiro[4.5]decane4-Piperidone ethylene acetal4-哌啶酮缩乙二醇4-哌啶酮缩乙二醇4-Piperidone ethylene ketal1,4-Dioxa-8-azaspiro[4.5]decane