.gamma.,.gamma.-Dimethylacetoacetic acid ethyl ester 7152-15-0 Ethyl 4-methyl-3-oxopentanoate Ethyl isobutyroylacetate Ethyl isobutyrylacetate NSC62029 Pentanoic acid, 4-methyl-3-oxo-, ethyl ester Valeric acid, 4-methyl-3-oxo-, ethyl ester