Efficient solid-phase synthesis of diverse 1,2,3-benzotriazin-4-ones using tert-butyl nitrite

An efficient synthesis of (−)-chrysolic acid and (+)-isofregenedol has been achieved from zamoranic acid and sclareol. The characteristic tetrahydronaphtalenic system was obtained by use of a cationic rearrangement of bicyclic systems adequately functionalized. The absolute configuration of the natural products was established using Sharpless asymmetric epoxidation.