Rearrangement Approaches to Cyclic Skeletons. I. Photochemical Rearrangement Approaches to (±)-Sesquicarene and (±)-Sirenin, [3–6] Fused-Ring Sesquiterpenes
作者:Tadao Uyehara、Jun-ichi Yamada、Koichi Ogata、Tadahiro Kato
DOI:10.1246/bcsj.58.211
日期:1985.1
The 4-alkyl, 4-alkenyl, and 4-aryl derivatives of bicyclo[3.2.2]nona-3,6-dien-2-one (9) were prepared from 9 itself by ultrasound-promoted Barbier reaction followed by PCC oxidation. Photochemical transformation of the 4-(4-methyl-3-pentenyl) derivative of 9, namely 13, in THF–water gave endo-7-[exo-7-(4-methyl-3-pentenyl)bicyclo[4.1.0]hept-2-ene]acetic acid (14). Acid 14 was converted into endo-7
双环[3.2.2]nona-3,6-dien-2-one (9) 的 4-烷基、4-烯基和 4-芳基衍生物是由 9 本身通过超声促进的 Barbier 反应和 PCC 氧化制备的. 9 的 4-(4-methyl-3-pentenyl) 衍生物,即 13,在 THF-水中的光化学转化得到内-7-[exo-7-(4-甲基-3-戊烯基)双环[4.1.0 ]庚-2-烯]乙酸(14)。酸 14 被转化为endo-7-methyl-exo-7-(4-methyl-3-pentenyl)bicylo[4.1.0]heptan-2-one (4),这是 (±)-sesquicarene 和 ( ±)警报素全合成。此外,通过光化学转化从 2-甲基托酮 (21) 制备的 13 的 1-甲基衍生物,完成了 (±)-倍半卡烯的高度立体定向全合成。