Isoanacardic aldehyde

Reduction of isoanacardic aldehyde gave a methylol which could also be synthesised directly from cardanol together with formation of some of the 4,6-bis-methylol. The monomethylol compound isoanacardic alcohol was an effective solvent extractant for the borate anion (ref. 279, 293). The isomeric compound, anacardic alcohol (ref. 88) was similarly obtained from anacardic acid (ref. 180). This In conjunction with the teriary amine Aliquat 336 was highly effective for the solvent extraction of the borate anion (ref. 293). Both these substances were comparable in properties to the 2,6-bis(hydroxymethyl) derivatives of 4-t nonylphenol and to 4-t octyl-2-chloro-6-hydroxymethylphenol (ref. 294). 

By Kolbe carbonation of cardanol in diglyme containing potassium hydroxide (ref. 283) (and of technical CNSL itself) isoanacardic acid was obtained. This was also another source of both the methylol and aldehyde, namely isoanacardic alcohol and isoanacardic aldehyde repectively. These transformations are illustrated in the preceding scheme. 

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