3,3-dimethyl-7,12-dihydro-6H-indolo[2,3-a]quinolizine-2,4-dione

ethyl 2,2-dimethyl-3-oxopent-4-enoate

Ethyl 5-hydroxy-2,2-dimethyl-3-oxopentanoate

2,4-二氢-4,4,5-三甲基-2-苯基-3H-吡唑-3-酮

1-diazonio-3,3-dimethyl-4-oxopent-1-en-2-olate