.gamma.-Hydroxy-.beta.-oxobutane 1-Hydroxyethyl methyl ketone 2,3-Butanolone 2-Butanone, 3-hydroxy- 2-Hydroxy-3-butanone 3-Hydroxy-2-butanone 513-86-0 ACETOIN Acetyl methyl carbinol Dimethylketol Methanol, acetylmethyl- NSC7609