Stereochemistry of an Ene Reaction Involving 1,7-Dienes; Bicyclo[3.3.1]nonanes from (3-Cyclohexenyl)diallylcarbinols
作者:Alan F. Thomas、Marina Lander-Schouwey
DOI:10.1002/hlca.19840670124
日期:1984.2.1
(3-Cyclohexenyl)diallylcarbinols undergo a thermal retro-enereaction to give crotonylcyclohexenes at ca. 200°. A side-reaction is an enereaction to give bicyclo[3.3.1]nonanes. These become the main products above 300°. The stereochemistry of 2-allyl-1,4,6-trimethylbicyclo[3.3.1]-6-none-2-ols and related compounds is discussed, and a case is described in which the allyl group is not freely rotating.
Synthesis of (E)-1-Propenyl Ketones from Carboxylic Esters and Carboxamides by Use of Mixed Organolithium-Magnesium Reagents. Synthesis of ?-Damascone, ?-Damascone, and ?-Damascenone
作者:Charles Fehr、Jos� Galindo
DOI:10.1002/hlca.19860690127
日期:1986.2.5
The novel reagents formed by combination of allylmagnesium chloride and a strong non-nucleophilic lithium base (LiNR2) convert non- or slowly enolizable carboxylic esters or carboxamides into 2-propenyl ketones which are protected from further reaction by their in situ conversion into enolates. This modified Grignardreaction is applied to efficient syntheses of α-damascone, β-damascone, β-damascenone