Intramolecular Cyclization of Nerol and the Related Attack of (<i>Z</i>)-Allylic Alcohol Moiety on the Terminal Olefin Linkage as Induced by TiCl<sub>4</sub>–PhNHMe Complex. Synthesis of Nezukone
作者:Akira Itoh、Tadashi Saito、Koichiro Oshima、Hitosi Nozaki
DOI:10.1246/bcsj.54.1456
日期:1981.5
selectivity. Cyclization of (2Z) isomers of CH2=CR–CH2CH2CMe=CHCH2OH (R=H, Me, Cl) produced seven-membered carbocyclic products in fair yields. The novel procedure has been utilized in the synthesis of nezukone from (2E)-3-isopropyl-2,6-heptadien-1-ol involving five steps.
在 -23 °C 的二氯甲烷中,在 TiX4–PhNHMe (1:1) 络合物 (I, X= Cl, Br) 存在下,橙花醇被环化为萜品基氯或溴化物,香叶醇通过简单的卤化作用转化为香叶基卤化物。(2Z,6E) 构型的末端改性衍生物 YCH2C(Me)=CHCH2CH2CMe=CHCH2OH (Y=SiMe3, SnBu3) 通过用 I 处理环化,以高产率和 100% 选择性提供柠檬烯。CH2=CR–CH2CH2CMe=CHCH2OH(R=H,Me,Cl)的(2Z)异构体的环化以合理的产率产生了七元碳环产物。该新方法已用于从 (2E)-3-isopropyl-2,6-heptadien-1-ol 合成 nezukone,包括五个步骤。