Stereochemical aspects of the intramolecular Diels-Alder reactions of deca-2,7,9-trienoate esters. 3. Thermal, Lewis acid catalyzed, and asymmetric cyclizations
Site-Selective<i>trans</i>-Hydrostannation of 1,3- and 1,<i>n</i>-Diynes: Application to the Total Synthesis of Typhonosides E and F, and a Fluorinated Cerebroside Analogue
site‐selectivity, whereas per‐stannylation is favored when the reaction is carried out in the cold. This counterintuitive trend can be rationalized based on spectroscopic data; additional support comes from the isolation of the unusual bimetallic complex 11. The bridging fulvene and enynyl ligands in 11 are thought to reflect an interligand redox isomerization process likely triggered by synchronous activation
Thermal rearrangement of divinylcyclopropane systems. Preparation of functionalized, stereochemically defined bicyclic and tricyclic products containing the bicyclo[3.2.1]octane skeleton
作者:Edward Piers、Grace L. Jung、Neil Moss
DOI:10.1016/0040-4039(84)80040-4
日期:——
A study involving the preparation and thermolysis of substituted 6--(1-alkenyl)bicyclo[3.1.0]hex-2-ene systems (14, 15, 23, 29, 40) shows (a) that C-8 functionalized bicyclo[3.2.1]octa-2,6-dienes can be prepared readily this methodology (14 → 16; 15 → 17), (b) that the rearrangement reaction is stereospecific even when the 6-(1-alkenyl) group is substituted with a sterically bulky isopropyl group (23
On the Diels–Alder reactions of pentadienyl maleates and citraconates
作者:Tory N. Cayzer、Michael J. Lilly、Rachel M. Williamson、Michael N. Paddon-Row、Michael S. Sherburn
DOI:10.1039/b501446h
日期:——
Reactions between conjugated dienols and maleic anhydride provide either cis-fused or trans-fused bicyclic products as major products, depending upon how the reaction is carried out. Simply mixing the two reactants together generally leads to cis-fused lactone acids in thermal reactions which proceed viaintermolecular Diels-Alderreaction followed by intramolecular esterification. Pre-forming the maleate
Enantioselective 6-endo bromoaminocyclization of 2,4-dienyl N-tosylcarbamates catalyzed by a chiral phosphine oxide-Sc(OTf)<sub>3</sub> complex. A dramatic additive effect
作者:Hu Huang、Hongjie Pan、Yudong Cai、Mao Liu、Hua Tian、Yian Shi
DOI:10.1039/c5ob00001g
日期:——
This paper describes an effective enantioselective 6-endo bromoaminocyclization of 2,4-dienyl N-tosylcarbamates catalyzed by a chiral phosphine oxide-Sc(OTf)3 complex with a dramatic additive effect.