Primary alcohols biologically important

Cholesterol is an important constituent of biological membranes, whereas cholesteryl esters occur in vast amounts in the lipoproteins of blood (Zschornig et al. 2006). In comparison to cholesterol that possesses amphiphilic properties due to its hydroxyl group, cholesteryl esters are completely apolar molecules. As typical of apolar molecules, cholesteryl esters (as well as di- and triacylglycerols) are exclusively detected as Na but never as adducts, whereas cholesterol-as a primary alcohol-is exclusively detected as protonated molecule subsequent to water elimination, i.e. cholesterol is detected at m/z = 369.3, although its monoisotopic mass is 386.3 (Schiller et al. 2000). Some additional important aspects will be discussed below in the context of blood. 

Aldehydes and ketones are among the most important of all compounds, both in the chemical industry and in biological pathway. In this chapter, we ve looked at some of their typical reactions. Aldehydes are normally prepared in the laboratory by oxidation of primary alcohols or by partial reduction of esters. Ketones are prepared by oxidation of secondary alcohols. 

Fluorinated carbohydrates have recently received much attention because of their importance in the study of the enzyme-carbohydrate interactions and their interesting biological activity [56], Hara et al. [57] achieved the deoxyfluorination of primary and anomeric hydroxyl groups of a series of protected carbohydrates, for example 65 into 66 (70%) (Scheme 12.31, a representative example) and 67 into 68 (90%) (Scheme 12.32, a representative example), with good yields, by use of N,N-diethyl-a,a-difluoro-(m.-methylbenzyl)amme (DFMBA), which has previously proved to be a selective reagent for the synthesis of fluorinated alcohols and carboxylic acids [58], Chemoselective deoxyfluorination at the anomeric position... 

Sterols are a class of lipids containing a common steroid core of a fused four-ring structure with a hydrocarbon side chain and an alcohol group. Cholesterol is the primary sterol lipid in mammals and is an important constituent of cellular membranes. Oxidization and/or metabolism of cholesterol yield numerous oxysterols, steroids, bile acids, etc., many of which are important signaling molecules in biological systems. Cholesteryl esters esterified with a variety of fatty acyls are enriched in... 

---