Stereodefined Substituted Cyclopropyl Zinc Reagents from Gem-Bismetallics
作者:Dov Beruben、Ilane Marek、Jean F. Normant、Nicole Platzer
DOI:10.1021/jo00113a032
日期:1995.4
1,1- or n,n-Bismetallic reagents bearing a methoxymethyl ether in the gamma position undergo cyclization at room temperature to give monometalated, diastereoselectively substituted cyclopropanes, The nature of the substituents is crucial for this diastereoselection, a pi-chelation between one metal and a properly located unsaturation, as well as 1,2-strain, are proposed to explain the steric outcome of these reactions.
1,4-Hydroiodination of Dienyl Alcohols with TMSI To Form Homoallylic Alcohols Containing a Multisubstituted <i>Z</i>-Alkene and Application to Prins Cyclization
作者:Yongjin Xu、Zhiping Yin、Xinglong Lin、Zubao Gan、Yanyang He、Lu Gao、Zhenlei Song
DOI:10.1021/acs.orglett.5b00485
日期:2015.4.17
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.
The organic synthesis using haloboration reaction 20. A simple synthesis of (2-Bromoallyl)diphenoxyborane by the bromoboration of allene and its reaction with carbonyl compounds
作者:Shoji Hara、Akira Suzuki
DOI:10.1016/s0040-4039(00)93593-7
日期:1991.11
Bromoboration reaction of allene with boron tribromide, followed by the treatment with anisole gives (2-bromoally)diphenoxyborane which reacts with aldehydes and ketones to give 2-bromohomoallylic alcohols in excellent yields.
TMSBr/InBr<sub>3</sub>-promoted Prins cyclization/homobromination of dienyl alcohol with aldehyde to construct cis-THP containing an exocyclic E-alkene
作者:Linjie Li、Xianwei Sun、Yanyang He、Lu Gao、Zhenlei Song
DOI:10.1039/c5cc06270e
日期:——
A TMSBr/InBr3-promoted Prins cyclization/homobromination reaction of dienyl alcohol with aldehyde has been developed to construct a unique cis-E THP shown as the A ring in (−)-exiguolide and the B ring in bryostatins.