(+/-) alpha,beta-dihydroxyisovaleric acid (R)-2,3-dihydroxy-3-methylbutanoate 1756-18-9 2,3-dihydroxy-3-methylbutanoate 2,3-dihydroxyisovaleric acid 3-methyl-2,3-dihydroxybutyric acid Butyric acid, 2,3-dihydroxy-3-methyl- alpha,beta-dihydroxyisovalerate butanoic acid, 2,3-dihydroxy-3-methyl