84. Total synthesis of (±)-Δ⁹(¹²)-capnellene via iterative intramolecular type-I-“Magnesium-ene” reactions
    Oppolzer, W.; Bättig, K.
    Tetrahedron Lett. 1982, 23, 4669-4672

The marine triquinane sesquiterpene Δ⁹(¹²)-capnellene (1) was synthesised from 2,2,5-trimethyl-5-hexenal (2) by a sequence of all synthetic operations in 5% overall yield. The key steps 3 → 4 → 5 → 6 involve two intramolecular type-I-“Mg-ene” processes.

DOI : 10.1016/S0040-4039(00)85683-X