4alpha,5beta-5,20-epoxytax-11-ene-4-ol + reduced [NADPH--hemoprotein reductase] + O2 => 4alpha,5beta-5,20-epoxytax-11-ene-4,9-diol + oxidized [NADPH--hemoprotein reductase] + H2O + H(+)
4alpha,5beta-5,20-epoxytax-11-ene-4-ol + reduced [nadph--hemoprotein reductase] + o2 => 4alpha,5beta-5,20-epoxytax-11-ene-4,9-diol + oxidized [nadph--hemoprotein reductase] + h2o + h(+)