Masked o-benzoquinone strategy in organic synthesis: Short and efficient construction of cis-decalins and linear triquinanes from 2-methoxyphenols

The inter- and intramolecular Diels–Alder reactions of masked o-benzoquinones generated in situ from the oxidation of easily accessible 2-methoxyphenols with diacetoxyiodobenzene or bis(trifluoroacetoxy)iodobenzene provided cycloadducts in excellent regio- and stereoselectivity and good yields. A general approach to the synthesis of highly substituted cis-decalins and triquinanes with complete stereocontrol from the cycloadducts has been developed. The applicability of our methodology is demonstrated by the total syntheses of several natural products.