3-chloro-1,5-dioxaspiro[5.5]undec-3-en-2-one

1,1-二乙氧基乙烯

5-chloro-2,2-diethoxy-2,3-dihydropyran-4-one

5-chloro-2-methoxy-2-t-butyldimethylsilyloxy-2,3-dihydropyran-4-one

3,5-dichloro-4-hydroxy-1H-pyridin-2-one