Intramolecular Diels-Alder reactions of trienes tethered with an ether linkage
作者:Peter J. Ainsworth、Donald Craig、John C. Reader、Alexandra M.Z. Slawin、Andrew J.P. White、David J. Williams
DOI:10.1016/0040-4020(95)00920-5
日期:1996.1
The intramolecularDiels-Alderreactions of a series of ether-tethered trienes 3a-3o show varying selectivities according to the nature of the dienophile-activating group and the presence of substituents in the linking chain. Some tether-cleaving reactions are reported.
(3R,5R)-Dimethylcyclohexanone was converted to chiral straight-chaincompounds with syndiotactic methyl function via intermolecular aldol condensation followed by ring cleavage reaction.
Kinetic Resolution of Chiral Cyclohex-2-enones by Rhodium(I)/binap-Catalyzed 1,2- and 1,4-Additions
作者:Andreas Kolb、Sebastian Hirner、Klaus Harms、Paultheo von Zezschwitz
DOI:10.1021/ol300387f
日期:2012.4.20
The feasibility of kinetic resolutions of racemic monosubstituted cyclohex-2-enones by Rh/binap-catalyzed reactions was investigated. 1,2-Addition of AlMe3 to the 5-substituted derivatives furnished allylic alcohols in the matched case, while the less reactive enantiomers were either left over or transformed into trans-3,5-disubstituted cyclohexanones in parallel or sequential 1,4-additions. Altogether, these represent regiodivergent reactions on racemic mixtures. In contrast, 1,4-addition of aryl groups led to inferior results since either catalyst or substrate control dominated.
Relative asymmetric induction in the hydroboration of bi-1-cyclohexen-1-yls