| Popis: |
The first synthesis of alliodorine 4EE, a constituent isolated from the duramen of a tropical tree: Cordia alliodora is reported. A mixture of E and Z isomers of 2-methyl-6-oxo-2-heptenenitrile 3 easily accessible by U.V. irradiation of 1-methyl-2-oxo-cyclopentanecarbonitrile 2 is used as starting material. E/Z isomerism is suppressed during a step of the synthesis reduction of the α,β-unsaturated nitrile function (E+Z) in the α,β-unsaturated aldehyde E (the ZE isomerisation occurs during the hydrolysis of the intermediate imine). The synthesis was conducted in six steps with an overall yield of 12,5% from 1-methyl-2-oxocyclopentanecarbonitrile 2. |
