1,4-Hydroiodination of Dienyl Alcohols with TMSI To Form Homoallylic Alcohols Containing a Multisubstituted Z-Alkene and Application to Prins Cyclization
摘要:
A regioselective 1,4-hydroiodination of dienyl alcohols has been developed using trimethylsilyl iodide as Lewis acid and iodide source. A range of homoallylic alcohols containing a multisubstituted Z-alkene was synthesized with good to excellent configurational control. The approach was applied in sequential hydroiodination/Prins cyclization to afford multisubstituted tetrahydropyrans diastereoselectively.
1,4-Hydroiodination of Dienyl Alcohols with TMSI To Form Homoallylic Alcohols Containing a Multisubstituted Z-Alkene and Application to Prins Cyclization
摘要:
A regioselective 1,4-hydroiodination of dienyl alcohols has been developed using trimethylsilyl iodide as Lewis acid and iodide source. A range of homoallylic alcohols containing a multisubstituted Z-alkene was synthesized with good to excellent configurational control. The approach was applied in sequential hydroiodination/Prins cyclization to afford multisubstituted tetrahydropyrans diastereoselectively.
In Turn or in Reverse Palladium-Catalyzed Carbonyl Allylation and Diels-Alder Reaction by 2-Methylene-3-buten-1-ol
作者:Yoshiro Masuyama、Manabu Fuse、Yasuhiko Kurusu
DOI:10.1246/cl.1993.1199
日期:1993.7
UsingPdCl2(PhCN)2-SnCl2, 2-methylene-3-buten-2-ol causes carbonylallylation of various aldehydes to afford 1-substituted-3-methylene-4-penten-1-ols; the Diels-Alder reaction of those with dienophiles produces 1-(2-hydroxyethyl)cyclohexenes. Diels-Alder reaction of 2-methylene-3-buten-1-ol with dienophiles followed by carbonylallylation produces structurally isomeric 1-methylene-2-(hydroxymethyl)cyclohexanes
The combination of Pd catalyst and Xantphos ligand in the presence of Et(3)B nicely promotes the allylation of aldehydes with conjugated dienes to provide dienyl homoallylalcohols in excellent yields. The reaction occurs selectively at the C-C double bond bearing higher electron density.
在 Et(3)B 存在下,Pd 催化剂和 Xantphos配体的组合很好地促进了醛与共轭二烯的烯丙基化,以优异的产率提供二烯基高烯丙醇。该反应选择性地发生在具有较高电子密度的 CC 双键上。