3-羟基-4-甲基-5-丙基呋喃-2(5H)-酮

甲基丙二酸二甲酯

1-O-ethyl 3-O-methyl 2-methylpropanedioate

carbon monoxide

1-O-ethyl 4-O-methyl 2-methyl-3-oxobutanedioate