Wolf-Kischner reduction

Yohimbine (36) is a well-known and reasonably available alkaloid from Corynanthe yohimbe, inter alia. For this reason, and partly because of its intrinsic pharmacological activity (including reputed aphrodisiac activity), chemists have frequently studied its properties. Oppenauer oxidation is usually attended by saponification and decarboxylation in this series, and yohimbone (37) is the product. Wolf-Kischner reduction to yohimbane (38), followed by sodium hydride mediated alkylation, leads to the analgesic agent, mimbane (39). °... 

Reaction of the potassium salt of salicylaldehyde with chlo-roacetone affords first the corresponding phenolic ether aldol cyclization of the aldehyde with the ketonic side chain affords the benzofuran (1). Reduction of the carbonyl group by means of the Wolf-Kischner reaction affords 2-ethyl-benzofuran. Friedel-Crafts acylation with anisoyl chloride proceeds on the remaining unsubstituted position on the furan ring (2). The methyl ether is then cleaved by means of pyridine hydrochloride (3). lodina-tion of the phenol is accomplished by means of an alkaline solution of iodine and potassium iodide. There is thus obtained benziodarone (4)... 

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See also in sourсe #XX -- [ , ]

See also in sourсe #XX -- [ ]

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