Photochemistry of 2-methylene-1,2,3,4-tetrahydro-1,4-methanonaphthalene in protic media. A novel photoinduced anti-Markovnikov addition to the double bond

Irradiation of 2-methylene-1,2,3,4-tetrahydro-1,4-methanonaphthalene (I) in acidic methanol leads to three products (II), (III), and (IV); the formation of (II) represents a novel anti-Markovnikov addition of methanol across the methylene double bond.