Intramolecular [2 + 2]-Photocycloadditions of 6-Allyl-2-cyclohexenones. Formation of Tricyclo[3.3.1.0<sup>2,7</sup>]nonan-6-ones and Tricyclo[4.2.1.0<sup>3,8</sup>]nonan-7-ones
作者:Wolfgang Fröstl、Paul Margaretha
DOI:10.1002/hlca.19760590639
日期:——
Alkylation of 4,4,6-trimethyl-2-cyclohexenone (1) in toluene in the presence of sodium bis(trimethylsilyl)amide proceeds smoothly to give high yields of compounds 2. Irradiation (λ= 366 nm) of the 6-allyl-4,4,6-trimethyl-2-cyclohexenones 2a–c yields mixtures of the isomeric tricyclo-nonanones 3 and 4, the product ratio depending on the substituent R' of the allylic side chain and on the solvent. The
在双(三甲基甲硅烷基)酰胺钠存在下,甲苯中的4,4,6-三甲基-2-环己烯酮(1)烷基化反应顺利进行,从而获得高收率的化合物2。对6-烯丙基-4,4,6-三甲基-2-环己烯酮2a–c进行辐照(λ= 366 nm),得到三环壬酮异构体3和4的混合物,产物比取决于取代基R'的取代基R'。烯丙基侧链并在溶剂上。给出了环化的量子产率。