2-Azaspiro[5.5]undec-1-ene 、 2-Azaspiro[7.5]tridec-1-ene 以3,3-diethyl-3,4,5,6-tetrahydropyridine and 2-azaspiro[5.5]undeca-1,7-diene there is obtained (Example 20A) 2-azaspiro-[7.5]tridecane, b.p. 85°-87° C./0.1 mm的产率得到3,3-diethyl-3,4,5,6-tetrahydropyridine