43 Δ^<9(12)>-Capnellene-3β,8β,10α-triolの合成研究

概要

論文の詳細を見る
Studies directed toward the first total synthesis of Δ^<9(12)>-capnellene-3β, 8β, 10α-triol(3) is reported. In the first part of this presentation, development of a general synthetic route to the bisallylic alcohol functionality, which is uniquely associated with the capnellane alcohols(1〜6), is described. Transformation of the simple ketone(9) to the bisallylic alcohol(8), which involves the reaction of the epoxide(21) with trimethylsilyl-lithium in HMPA as a key step, proceeded quite nicely in ca. 16% overall yield. Cyclization of the β-keto ester(13), probably a mixture of the stereoisomers, afforded the stereochemically homogeneous tricycle(15) via base-induced epimerization. In the second, synthesis of the key intermediate(22) for Δ^<9(12)>-capnellene-3β, 8β, 10α-triol(3) is presented. Retrosynthetic analysis is based on cyclization of the allylsilane(25) to 34. Along this line, the key intermediate(22) has been obtained from 1,3-cyclohexadiene in a stereocontrolled manner. In the third, synthetic approach to Δ^<9(12)>_capnellene-3β, 8β, 10α-triol(3) is discussed. This approach involves the same synthetic sequence described above(9→8). Conversion of 22 to the tricycle(41,) has been already accomplished. Transformation of 41 to the natural product(3) is currently under investigation.
天然有機化合物討論会の論文
1983-09-15