Methyl 2-acetyl-3-oxobutanoate4619-66-342 % similar 2,5-Dimethyl-3(2H)furanone14400-67-040 % similar Methyl 2-chloroacetoacetate4755-81-132 % similar 2-Acetylbutyrolactone517-23-732 % similar Tetrahydrocyclobuta[1,2-C:3,4-C′]difuran-1,3,4,6-tetrone4415-87-630 % similar Ethyl 2-methylacetoacetate609-14-330 % similar