Carbon hydroxylation of alkyltetrahydropyranols: A paradigm for spiroacetal biosynthesis in Bactrocera sp.

[GRAPHICS] In a number of Bactrocera species the penultimate step in the biosynthesis of spiroacetals is shown to be the hydroxylation of an alkyltetrahydropyran ol followed by cyclization, The monooxygenases that catalyze this side chai n hydroxylation show a strong preference for oxidation four carbons from th e hemiketal center, to produce the spiroacetal, The hydroxy spiroacetals ob served in Bactrocera appear to derive from direct oxidation of the parent s piroacetals and not from alternate precursors.