Tertiary alcohols compounds

The useful biological properties of paclobutrazol have inspired further chemical synthesis of azole structures, culminating with the discovery of a series of tertiary alcohol compounds. The original synthetic strategy was conceived as a disconnection and reconnection analysis from paclobutrazol (Figure 5). These early compounds were good fungicides and further optimisation in this area has led to the commercial introduction of two products flutriafol and recently hexaconazole. 

In paclobutrazol A and D of Figure 7 are substituted, producing a stabilised gauche conformation. By substituting at A and B, but leaving C and D as hydrogen it is possible to generate tertiary alcohol compounds with all the correct requirements for... 

Alcohols and alkyl halides are classified as primary secondary or tertiary according to the degree of substitution of the carbon that bears the functional group (Section 2 13) Thus primary alcohols and primary alkyl halides are compounds of the type RCH2G (where G is the functional group) secondary alcohols and secondary alkyl halides are compounds of the type R2CHG and tertiary alcohols and tertiary alkyl halides are com pounds of the type R3CG... 

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... 

Addition of Grignard reagents and organolithium compounds (Sections 14 6-14 7) Aldehydes are converted to secondary alcohols and ketones to tertiary alcohols... 

Formic acid forms esters with primary, secondary, and tertiary alcohols. The high acidity of formic acid makes use of the usual mineral acid catalysts unnecessary in simple esterifications (17). Formic acid reacts with most amines to form formylamino compounds. With certain diamines imida2ole formation occurs, a reaction that has synthetic utiHty (18) ... 

The reaction of alcohols and acid chlorides in the presence of magnesium has been described (68). With primary and secondary alcohols the reaction is very smooth, and affords high and sometimes quantitative yields. Difficulty esteritiable hydroxy compounds such as tertiary alcohols and phenols can be esteritied by this method. The reaction carried out in ether or benzene is usually very vigorous with evolution of hydrogen. 

Stability study was run on model compound urethanes and the data are shown in Fig. 11. It is apparent from the study that urethanes based on primary hydroxyls should have better thermal stability than those based on secondary or tertiary alcohols. 

In some cases products of rearrangement are obtained either partially or exclusively on treatment of Grignard reagents with epoxides. Thus, reaction of the 2/ ,3/ -epoxide (14) with methyl Grignard reagent affords a mixture of two epimeric secondary A-nor alcohols (15) in 80% yield and the tertiary hydroxy compound, 2a-methyl-5a-cholestan-2/f-ol (16) in 15 % yield. ... 

Terminally unsaturated fluonnated alkenoic acids can be obtained from poly-fluorocycloalkenes by reaction with potassium hydroxide m rert-butyl alcohol [24] (equation 26) The use of a tertiary alcohol is critical because primary and secondar y alcohols lead to ethers of the cycloalkenes The use of a polar aprotic solvent such as diglyme generates enols of diketones [26] (equation 27) The compound where... 

These studies show that the perfluoroalkyletherlithium compound shown in equation 42 has greater thermal stability than the perfluorooctyllithium, which must be prepared in situ. This in situ process has been very useful in the synthesis of other shorter chain perfluoroalkyllithium compounds Pentafluoroethyllithium can be conveniently prepared in this manner and reacts with numerous esters to yield tertiary alcohols [76, 77] in excellent yields. 

A variant of the Williamson ether synthesis uses thallium alkoxides. The higher reactivity of these can be of advantage in the synthesis of ethers from diols, triols and hydroxy carboxylic acids, as well as from secondary and tertiary alcohols on the other hand however thallium compounds are highly toxic. 

The rearrangement of an ether 1 when treated with a strong base, e.g. an organo-lithium compound RLi, to give an alcohol 3 via the intermediate a-metallated ether 2, is called the Wittig rearrangement. The product obtained is a secondary or tertiary alcohol. R R can be alkyl, aryl and vinyl. Especially suitable substrates are ethers where the intermediate carbanion can be stabilized by one of the substituents R R e.g. benzyl or allyl ethers. 

The substitution of the lone proton on the benzhydryl carbon by a methyl group again affords compounds with antihistamine activity. Reaction of an appropriate acetophenone (21) with phenyl-magnesium bromide affords the desired tertiary alcohols (22). 

CMe2=CH. CH2. CH . CHMe. CH. CHMeOH, has the same odour but more pronounced, and suggestive of tea roses. 2 Di-methyl-critronellol, CMe2=CH. CH. CH. CHMe. CHaCMe OH, has the rose odour but is also slightly camphoracious (as is to be expected with a tertiary alcohol) 1 ethyl citronellol has a very fine odour of roses and 2 di-ethyl-citronellol is like the di-methyl compound but the rose odour is more pronounced 1 phenyl citronellol is very strong. 

Rather similar was the paper [PolG36a] which also derives asymptotic formulae for the number of several kinds of chemical compounds, for example the alcohols and benzene and naphthalene derivatives. Unlike the paper previously mentioned, this one gives proofs of the recursion formulae from which the asymptotic results are derived. A third paper on this topic [PolG36] covers the same sort of ground but ranges more broadly over the chemical compounds. Derivatives of anthracene, pyrene, phenanthrene, and thiophene are considered as well as primary, secondary, and tertiary alcohols, esters, and ketones. In this paper Polya addresses the question of enumerating stereoisomers -- a topic to which we shall return later. 

As examples of their addition to carbonyl compounds, Grignard reagents react with formaldehyde, H2C = 0, to give primary alcohols, with aldehydes to give secondary alcohols, and with ketones to give tertiary alcohols. 

Perhaps the most valuable reaction of alcohols is their oxidation to yield car-bony compounds—the opposite of the reduction of carbonyl compounds to yield alcohols. Primary alcohols yield aldehydes or carboxylic acids, secondary alcohols yield ketones, but tertiary alcohols don t normally react with most oxidizing agents. 

Acid halides are among the most reactive of carboxylic acid derivatives and can be converted into many other kinds of compounds by nucleophilic acyl substitution mechanisms. The halogen can be replaced by -OH to yield an acid, by —OCOR to yield an anhydride, by -OR to yield an ester, or by -NH2 to yield an amide. In addition, the reduction of an acid halide yields a primary alcohol, and reaction with a Grignard reagent yields a tertiary alcohol. Although the reactions we ll be discussing in this section are illustrated only for acid chlorides, similar processes take place with other acid halides. 

Acid-catalyzed solvolysis of hydroxylactams to (m)ethoxylactams has already been discussed. Secondary or tertiary alcohols can also be used, though in the latter case yields are lower. The reverse reaction, viz. hydrolysis of the alkoxy compounds, is generally performed in aqueous acid. 

Write the formulas of the following compounds and state whether each one is a primary, secondary, or tertiary alcohol or a phenol (a) Tchloro-2-hydroxybenzene ... 

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