Types of Alcohols

In propan-l-ol the OH group is attached to a C atom which has two H atoms on it, i.e. it contains a CH2OH group. This is known as a primary alcohol. 

In propan-2-ol the OH group is attached to a C atom which itself is 

These have the same molecular formula but different structural formulae - so they are isomers (see Section 6.4.2). The only difference between them is that the OH group is in a different position in each molecule. Both structures have the same molecular formula C3H7OH. 

Propanol does not have a tertiary alcohol isomer. The first of the alcohol series to have these isomers is when = 4, C4H9OH. 

You might like to draw the other isomers of butanol, C4H9OH. There are two primary alcohols and one secondary alcohol. Can you name them Which has two optical isomers They have the same molecular formula but differ in their structural formulae, and also, in the case of the secondary alcohol, the arrangement of the atoms and groups in space. 

---

The student will doubtless be aware of the fact that methyl, ethyl, n-propyl and iso propyl alcohols are completely miscible with water. The solubilities of the higher aloohols decrease progressively as the carbon content increases. The solubilities of all types of alcohols with five carbon atoms or more are quite small. For the isomeric butyl alcohols the solubilities (g. per 100 g. of water at 20°) are n-butyl, 8 iso-butyl, 23 scc.-butyl, 13 ierl.-butyl, completely miscible. 

By analogy to the hydration of alkenes hydration of an alkyne is expected to yield an alcohol The kind of alcohol however would be of a special kind one m which the hydroxyl group is a substituent on a carbon-carbon double bond This type of alcohol IS called an enol (the double bond suffix ene plus the alcohol suffix ol) An important property of enols is their rapid isomerization to aldehydes or ketones under the condi tions of their formation... 

The type of alcohol produced depends on the carbonyl compound Substituents present on the carbonyl group of an aldehyde or ketone stay there—they become sub stituents on the carbon that bears the hydroxyl group m the product Thus as shown m Table 14 3 (following page) formaldehyde reacts with Grignard reagents to yield pri mary alcohols aldehydes yield secondary alcohols and ketones yield tertiary alcohols... 

Whenever a hydrocarbon backbone has two hydroxyl radicals attached to it, it becomes a special type of alcohol known as a glycol. The simplest of the glycols, and the most important, is ethylene glycol, whose molecular formula C2H4(OH)2. The molecular formula can also be written CHjOHCHjOH and may be printed as such on some labels. Ethylene glycol is a colorless, thick liquid with a sweet taste, is toxic by ingestion and by inhalation, and among its many uses is a permanent antifreeze and coolant for automobiles. It is a combustible liquid with a flash point of 240"F. 

Waxes make up the part of the fibers that can be extracted with organic solutions. These waxy materials consist of different types of alcohols, which cannot be solubilized in water as well as in several acids (palmitic acid, oleaginous acid, stearic acid) [18]. 

The presence of volatile components in alcohol ethoxylates (e.g., free alcohol) places some restriction on the level and type of alcohol ethoxylate that can be spray-dried. Volatile components cause pluming in spray tower emissions. These emissions can be minimized by using a peaked or narrow range ethoxylate or by postdosing the nonionic onto a previously spray-dried powder [36]. The peaked ethoxylate contains inherently less of the volatile components. 

For a list of references to the selective oxidation of various types of alcohol, see Kulkami, M.G. Mathew T.S. Tetrahedron Lett., 1990, 31, 4497. 

Secondly it is possible to carry out functional chromatography within the framework of a two-dimensional development [6-8]. The first separation is followed by an in situ reaction of the sample substance on the layer the chromatogram is then developed perpendicular to the direction of the first chromatogram (SRS technique). The decision concerning the type of alcohol, is then made on the basis of the positions of the chromatogram zones esters migrate appreciable further than their parent alcohols and acids. 

E (1999) Type of alcoholic beverage and risk of myocardial infarction , J Cardiol,... 

Scheme 12.2 shows various types of alcohols that are most susceptible to Mn02 oxidation. Entries 1 and 2 illustrate the application of MnOz to simple benzylic and allylic alcohols. In Entry 2, the Mn02 was activated by azeotropic drying. Entry 3 demonstrates the application of the reagent to cyclopropylcarbinols. Entry 4 is an application to an acyloin. Entry 5 involves oxidation of a sensitive conjugated system. 

Hirano M, Ohno I, Kitamura S, Nishioka T, Fujita Y (1973) Efficacy of the pyrethroid compound possessing a new type of alcohol moiety. Jpn J Sanit Zool 29 219-224... 

Although most ethanol is now produced from corn, research has been done on producing this type of alcohol fuel from cellulosic biomass products including energy crops, forest and agricultural residues, and MSW, which would provide much cheaper feedstocks. The process of chemically converting these cellulosic biomass feedstocks is more involved and until this process can be simplified the price of ethanol will remain high. 

A striking phenomenon which probably involves biochemical individuality is that of pathological intoxication. Occasionally an individual, who may be a habitual drinker or not, is afflicted. In a typical case the individual goes berserk and may commit all sorts of crimes and cause damage to property. After a subsequent long sleep he has no memory of his acts.9 This very special type of drunkenness is not caused by any special type of alcohol or necessarily by large amounts it fortunately happens only rarely, and involves only a few individuals. Whether certain individuals are peculiarly susceptible and have repeated typical attacks (these would be classed, no doubt, as alcoholic psychotics) is not clear in any event only certain rare individuals ever are in such a condition as to be susceptible. 

FIGURE 4.8 Chiral selectivity as a function of amount and type of alcohol modifiers in the mobile phase in SFC. Conditions Al-(2-heptyl)-p-tolylamide enantiomers as the analyte 250 mm X 4.6 mm ID column, 10 xm silica particles coated with celhtlose trihenxoate carhon dioxide and various types and amounts of modifiers = methanol, o = ethanol, A = 1-butanol, x = 2-propanol, and = 2-butanol 25°C flow rate 4.5 mL/min at 0°C UV detection at 229 nm average column pressure 140 bar. (Reprinted from Macaudiere, R et al. 1989. J. Chromatogr. Sci. 27 383-394. With permission.)... 

A novel type of alcohol is derived from benzene. If we replace one of the hydrogen atoms on the benzene ring with a hydroxyl group, we get phenol ... 

Ethanol (ethyl alcohol made from grains) Ethanol (C H OH) is one of many types of alcohol. Grain alcohol can be produced by fermentation of agricultural waste, corn, or other grains. Another method is the hydration of ethylene the reaction of water with ethylene (C H ), a reaction in which the alcohol molecule is formed the water is then split off by heat. 

The categories depend upon the number of carbon atom attached to the alcohol carbon atom. Figure 3-1 illustrates the three types of alcohols. Note the number of carbon atoms attached to the bold-faced carbon atoms. 

Tertiary alcohols dehydrate most readily, primary alcohols least readily, and, unsurprisingly, secondary alcohols are intermediate. This relates to the relative stability of the intermediate carbocation. The temperature and concentration of the acid depends upon the type of alcohol. A primary alcohol, such as ethanol, requires concentrated acid and a very high temperature (180 degrees Celsius), while a tertiary alcohol, such as t-butyl alcohol, requires 20 percent sulfuric acid at 85 to 90 degrees Celsius. The process follows an El mechanism and produces the thermodyncimically more stable product. 

A common analytic test used to classify alcohols is the Lucas test. This test is for alcohols with six or fewer carbon atoms (and therefore soluble in reagent mixture). They react with HCl/ZnCl2 to form an alkyl chloride, which is insoluble in the reaction mixture (causing the solution to turn cloudy). The time required for the reaction to occur indicates the type of alcohol. Table 3-1 summarizes the time required for each type of alcohol. 

Type of Alcohol Time Required to Form an Alkyl Chloride... 

In 1956 Gerhard Kolbe (1) published the first results that showed that spherical silica particles could be precipitated from tetraethoxysilane in alcohol solutions when ammonia was present as the catalyzing base. Several years later, in 1968, StOber, Fink, and Bohn (2) continued in this research area and published the frequently cited original article for the preparation of monodispersed silica particles form alkoxide solutions. StOber et al. improved the precipitation process and described the formation of exceptionally monodispersed silica particles. The final particle size could be controlled over a wide range from about 50 nm to 1 1/2 p,m. Variations of the particle size could be achieved by different means, e.g., temperature, water and ammonia concentration, type of alcohol (solvent), TEOS (tetraethoxysilane) concentration, or mixing conditions. 

Strong evidence indicates at least a familial pattern and perhaps a hereditary basis for some types of alcoholism ( 393). More recent data show that genotype accounts for approximately 33% of the overall variance in liability ( 394). In addition, specific neurocircuitry and neurochemical systems appear to be important in the etiology of alcoholism (395). Thus, positive reinforcement may be mediated by activation of g-aminobutyric acid (GABA) receptors, release of opioid peptides and dopamine, inhibition of glutamate receptors, and interactions with the 5-HT system. Furthermore, neurobehavioral effects of alcohol and their association with these various neurotransmitters serve as potential targets for novel drug therapies. 

The differences between 172°caic and r/2°comp are probably caused by the changes in the reaction media. In unpolar media, alcohols form telomeric, hydrogen bonded complexes (rings or chains) whose nature depend on the concentration(s) and the type of alcohol(s) [51]. When a competition experiment is compared to the addition of a single alcohol either the overall alcohol concentration can be chosen identical, or each alcohol concentration may be the same leading to a higher overall concentration. Indeed, in each case different selectivities were found [15]. 

The absorption ranges of the various types of alcohols appear in Table 3.2, below. These values are for neat samples of the alcohols. 

For many years, most efforts directed towards the development of solid-phase preparations of alcohols had been limited to the synthesis of biopolymers, such as oligonucleotides and oligosaccharides. Interest in the preparation and chemical transformation of all types of alcohol on insoluble supports only began to grow rapidly in the early 1990s, when chemists realized the potential of parallel solid-phase synthesis for high-throughput compound production. 

The goal of most studies of esterification reactions on insoluble supports has been the attachment of N-protected amino acids to polystyrene-derived alcohols. In recent years, however, the scope of esterifications has been expanded to other types of alcohol and acid. In the following section, the most important strategies for the preparation of esters on solid phase are discussed. These have been organized according to type of functionality that is initially linked to the support. 

---