3-hydroxy-3-(4-methylpent-3-en-1-yl)glutaryl-CoA = 3-(4-methylpent-3-en-1-yl)pent-2-enedioyl-CoA + H2O
3-hydroxy-3-(4-methylpent-3-en-1-yl)glutaryl-coa = 3-(4-methylpent-3-en-1-yl)pent-2-enedioyl-coa + h2o