Biosynthesis of verrucarins and roridins. 3. Incorporation of 3R)-(5-14C)-and at C(2)stereospecific tritiated mevalonate into verrucarol]

Separate experiments, involving incorporation of either (3R)-[5-¹⁴C]-mevalonate or each enantiomer of [2-³H]-mevalonate into verrucartin A and roridin A, indicate that hydroxylation at C(4) of the tricothecane skeleton, to yield verrucarol (4), proceeds with an overall retention of configuration; they confirm that C(8) and not C(10) is derived specifically from C(2) or mevalonate.