Natural products alcohol-amine conversion

Synthesis of the /3-amino methyl esters was accomplished by Grignard addition to aldehydes or epoxides to deliver the ho-moallylic alcohols. After conversion to the homoamino derivative as prescribed in the allylic alcohol to allylic amine conversion, ozonolysis delivered the targets in good yield, without loss of optical activity or nitrogen protection (eq 49). Numerous additional examples as well as synthetic possibilities exist for the synthesis of natural product fragments utilizing this methodology. 

Two further syntheses of (+)-epiquinamide (2104), another of the (—)-enantiomer e t-2104 and one of the racemic alkaloid also pre-date the clarification of the natural product s absolute configuration. The route by Tong and Barker used (S)-(—)-pipecohnic acid (192) as chiral precursor (Scheme 267).After Boc protection of the amine and conversion of the carboxylic acid into the aldehyde 2121, diastereoselective addition of the lithium anion of TBS-protected propargyl alcohol gave mainly the (R)-alkynol (—)-2122 (69%) as well as the separable (S)-product, which was isolated as the cyclic carbamate (—)-2123 (5%). Attempts to invert the configuration of 2122 by treating its mesylate with sodium azide also... 

Direct conversion of fatty alcohols to primary amines by reaction with ammonia is not commercially practised but new catalyst developments show improved yields with this technology [10]. However, production of dialkylamines from alcohols is practised particularly with C8-C10 alcohols due to the limited availability of the corresponding acids. Alcohols are commonly used in the manufacture of tertiary alkyldimethylamines either through reductive amination with dimethylamine or by conversion to the alkylhaUde followed by reaction with dimethylamine. Both primary and secondary amines can be reacted with alcohols to produce tertiary trialkyl amines [11]. The chain branching seen with some synthetic alcohols means that the derived amines are not identical to those from natural sources. 

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