Fatty alcohols trimethylsilyl ethers

In the Croteau and Fogerson study, the triperpenic alcohols and sterols were derivatized into their trimethylsilyl ether derivatives using bis-trimethylsilylacetamide. The isopropanol-chloroform extract contained higher amounts of sterols and triteipenic alcohols such as p-sitosterol and amyrin compared to the SF extract. This could be due to the high polarity of the extracting liquid solvent as opposed to the supercritical fluid, and the increased volatility of the silylated sterols and triteipenic compounds relative to our fatty acid methyl esters, in addition to these compounds, the isopropanol-chloroform extract reported earlier also contained ursolic acid, a polar triteipenic acid, which was not extracted with pure CO2. 

A few other special procedures are quoted elsewhere in this book Methods for preparing ozonides (pp. 406—409) and for formation of mercury(II)-acetate adducts of unsaturated lipids (p. 402) procedures for esterifying fatty acids with diazomethane (p. 175) and for acetylation of alcohols with acetic anhydride (p. 175). The procedures described for preparing trifluoroacetates or trimethylsilyl ethers can be applied to aliphatic alcohols. 

New fatty compounds have been synthesized in high yields using radical addition reactions. Alkyl 2-haloalkanoates have been added to the double bond of unsaturated fatty compounds to give y-lactones. 2-Haloalkanenitriles have been added as well to give 4- haloalkanenitriles. 2-Halo fatty compounds, e.g., methyl 2-bromopalmitate, have been added to alkenes, allyl alcohol, vinyl esters, and trimethylsilyl enol ethers to give interesting branched and functionalized compounds. Key features of the re-... 

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