Sodium isoeugenolate

Methyl-isoeugenol, CjiHj O, bears exactly the same relationship to isoeugenol as methyl-eugenol does to eugenol. It occurs naturally in the oil of Asarum arifolium, and can be obtained by the action of methyl iodide on isoeugenol sodium, or by isomerising methyl-eugenol by hot alcoholic potash. 

Synthesis from Eugenol. The sodium or potassium salt of eugenol is isomerized to isoeugenol by heating. Isomerization can also be carried out catalytically in the presence of ruthenium [164] or rhodium [165] compounds. 

Oxidation of olefinic side chains with ozone to form aromatic aldehydes gives erratic results and therefore other oxidants are employed. For this purpose, the most widely used oxidant is nitrobenzene in dilute alkali the mixture is allowed to react at moderate temperatures for several hours. Thus, hydroxy benzaldehydes may be obtained from propenyl-phenols, which in turn are readily prepared by the Claisen rearrangement of Oalkyl ethers (method 100). Sodium dichromate in the presence of sulfanilic acid, which removes the aldehyde as it is formed, gives yields as high as 86% in the oxidation of isoeugenol and isosafrole. ... 

Nitro compounds in alkaline medium are used for rather specific oxidations. 2-Nitropropane in the form of its sodium salt converts benzylic halides into aromatic aldehydes under fairly mild conditions [987. Nitrobenzene transforms isoeugenol [95S] and similar aromatic compounds with side chains that contain double bonds conjugated with the aromatic rings into aldehydes [988, 989], In the Skraup synthesis, nitrobenzene dehydrogenates the dihydroquinoline intermediate to quinoline. 

Model Type C, the isoeugenol-maleic anhydride copolymer, forms an organic azide and isocyanate by the sodium azide pathway as is indicated by the IR spectra (A and B) of Figure 7. However, overall isocyanate yields remain low. 

A special case is the formation of o- and / -hydroxybenzaldehydes from the appropriate arylethylene derivatives by means of nitrobenzene and alkali, e.g., the production of vanillin from isoeugenol by two hours heating with nitrobenzene and 2N-sodium hydroxide solution at 180° under pressure 112... 

Isoeugenol to Vanillin. The formation of vanillin from eugenol is an example of an oxidation of a side chain to an aldehydic group in which it is convenient to protect one substituent against oxidation. Eugenol obtained from oil of cloves is heated with an alkali such as sodium hydroxide to convert it to isoeugenol, the hydroxyl group is protected by acetylation, and the substance is oxidized and then saponified to vanillin. 

The typical example of 1,2-addition reaction with singlet oxygen is the photosensitized oxidation of isoeugenol (Eskin, 1979). On sensitized photo-irradiation in sodium a solution of hydroxide, the isoeugenol molecule is attacked by singlet oxygen to form a di-oxetane intermediate 28, which is then converted to a vanillin (Scheme 26). Methylene blue is the most effective sensitizer in terms of vanillin yield. 

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