Applications of bridgehead alkenes to organic synthesis. Regio- and stereochemical control in the Diels-Alder route to polyfunctional cyclohexenes and cyclohexanes
A Cu‐catalyzeddiastereo‐ and enantioselective borylative coupling reaction of 1,3‐dienes with imines was realized. Branched homoallylic amines are readily prepared in a syn‐selective manner with high regio‐, diastereo‐ and enantioselectivity. Moreover, these three‐component coupling reactions feature good functional‐group compatibility and easy access to the substrates and catalyst.
Bridgehead dienes. Thermal generation of the bicyclo[3.3.1]nona-1(2),4(5)-diene (ZZ) ring system
作者:K.J. Shea、L.D. Burke
DOI:10.1016/s0040-4039(01)80975-8
日期:1987.1
The bicyclo[3.3.1]nona-1(1),4(5)-diene (ZZ) ring system has been generated by intramolecular Diels-Alder cycloaddition of methyl 7-methylene-non-2-yn-8-enoate. This highly strained bridgehead diene undergoes a homo 1,5-hydrogen shift to yield a [3.3.1] propellane product.
Isoprene has been metalated in tetrahydrofuran with an excess of sterically hindered potassium dialkylamides, prepared by combining equimolar amounts of the corresponding lithium amide and potassium tert-butoxide. Subsequent reaction with oxirane, alkyl bromides, and pivaldehyde gave the expected coupling products in reasonable yields. Coupling with (CH3)2CHCH2CHO and (CH3)2CCHCHO afforded the bark
Stereoselective [4+2]‐Cycloaddition with Chiral Alkenylboranes
作者:Dongshun Ni、Brittany P. Witherspoon、Hong Zhang、Chen Zhou、K. N. Houk、M. Kevin Brown
DOI:10.1002/anie.202000652
日期:2020.7.6
A method for the stereoselective [4+2]‐cycloaddition of alkenylboranes and dienes is presented. This transformation was accomplished through the introduction of a new strategy that involves the use of chiral N‐protonated alkenyl oxazaborolidines as dieneophiles. The reaction leads to the formation of products that can be readily derivatized to more complex structural motifs through stereospecific transformations
The Diels-Alder reaction with 6-methylene-7-octenoic acid, a functionalised butadiene
作者:G. Cardinale、J. A. M. Laan、J. P. Ward
DOI:10.1002/recl.19871060205
日期:——
A novel functionalisedbutadiene, 6-methylene-7-octenoicacid, was synthesized from myrcene (7-methyl-3-methylene-1,6-octadiene). Diels-Alder adducts were formed with maleic anhydride and cyclopentene-3,5-dione.