73. A Short and Efficient Synthesis of (±)-Modhephene by a Stereoelectronically-Controlled Ene-Reaction
    Oppolzer, W.; Bättig, K.
    Helv. Chim. Acta 1981, 64, 2489-2491

(±)-Modhephene (6) has been synthesized from the easily available trimethylpentalenone 1 in 6 steps in 26% overall yield (Scheme 2). The remarkably smooth 1,4-addition/enolate trapping 1 → 2 and subsequent selenoxide elimination after oxidation furnished the key intermediate 3 which underwent an expedient and highly stereoselctive intramolecular ene-reaction to give the propellane 4, readily convertible to (±)-6.

DOI : 10.1002/hlca.19810640756