Involved in the biosynthesis of solavetivone, a potent antifungal phytoalexin. Catalyzes the successive and independent hydroxylations of premnaspirodiene and solavetivol. The first hydroxylation step is 3-fold more efficient than the second hydroxylation reaction. (-)-vetispiradiene + 2 O2 + 2 reduced [NADPH--hemoprotein reductase] = 2 H(+) + 3 H2O + 2 oxidized [NADPH--hemoprotein reductase] + solavetivone Belongs to the cytochrome P450 family.