Alcohols, acetylation identification

Preparative HPLC was used to separate sterols and triterpene alcohols from the unsaponifiable matter in plant oils from Camellia weiningensis L., Brassica juncea L., and Microula sikkimensis. The isolated compounds were acetylated and further purified by AgN03-impregnated silica gel preparative thin layer chromatography (TLC). The identification was done by IR and MS. 

Identification and Gas-Liquid Chromatographic Behavior of Plasmalogen Aldehydes and Their Acetal, Alcohol, and Acetylated Alcohol Derivatives... 

Esterification with acid anhydrides is very widespread, especially for preparative use. Acetyl derivatives are prepared by reacting alcohols with acetic anhydride for identification purposes this method is mainly used with polyhydric alcohols (see p. 311) and with higher-molecular alcohols (sterols, etc.). The alcohol is heated in acetic anhydride, usually in the presence of anhydrous sodium acetate, or also in pyridine, chloroform, or benzene solutions. The isolation is carried out either by diluting the reaction... 

Formyl and acety derivatives of aliphatic amines are, as a rule, oils or low-melting substances and they are therefore not very suitable for identification. On the contrary, acetylated aromatic amines are very suitable for identification because they crystallize well and have sharp melting points distributed over a broad temperature range. Identification constants of practically all acetyl derivatives are known, which is an additional advantage. Acetyl derivatives are usually crystallized from water or alcohol, or a mixture of both, as well as from benzene, cyclohexane (or a mixture of these), or ethyl acetate. 

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