Primary alcohols aldehydes

The type of alcohol produced depends on the carbonyl compound. Substituents present on the car bonyl group of an aldehyde or ketone stay there—they become substituents on the carbon that bears the hydroxyl group in the product. Thus as shown in Table 14.3 (following page), formaldehyde reacts with Grignard reagents to yield primary alcohols, aldehydes yield secondary alcohols, and ketones yield tertiary alcohols. 

This can be used for oxidations in aqneons base of primary alcohols, aldehydes, activated alkyl halides, ctT-diols and nitroalkanes to carboxylic acids, and of secondary alcohols and secondary halides to ketones. 

Conversion of Boranes to Primary Alcohols, Aldehydes, or Carboxylic Acids... 

Furan is a colorless liquid, boiling point 32°C. insoluble in water, soluble in alcohol or ether. Furan vapor produces a green coloration on pine wood moistened with hydrochloric acid. Furan may he made from mucic acid. COOHtCHOHLCOOH. by dry distillation into pyromneie acid, C4H1O - COOH. and then heating the latter under pressure at 270 C. Furan derivatives arc known, namely, methyl, primary alcohol, aldehyde, carboxylic acid, in which the group attachment is at carbon number 2 ... 

The nature of the products obtained is dependent on the choice of oxidant, the structure suirounding the double bond, the reaction conditions, and the woik-up procedures. In general, if the double-bonded carbon is tertiary, then ketones or secondary alcohols can be easily obtained. However, if the carbon is secondary, the products will be primary alcohols, aldehydes or, most likely, carboxylic acids. Because they are very susceptible to further oxidation, the most chfficult of these products to obtain are the aldehydes. Selective oxidants and mild conditions are required to produce good yields. 

Oxidation Products of Ethane —Oxalic acid is thus the simplest di-carboxy acid possible. It may be considered as derived from ethane by the oxidation of both methyl groups to primary alcohol, aldehyde, and carboxyl groups successively. The entire series of oxidation relationships, including all of the intermediate compounds which we have already discussed, may be represented as follows ... 

Aromatic aldehydes, and aliphatic ones with no a hydrogen, give the Cannizzaro reaction when treated with NaOH or other strong bases.In this reaction, one molecule of aldehyde oxidizes another to the acid and is itself reduced to the primary alcohol. Aldehydes with an a-hydrogen do not give the reaction, because when these compounds are treated with base the aldol reaction (16-34) is much faster. Normally, the best yield of acid or alcohol is 50% each, but this can... 

Primary, secondary, and tertiary amines yield N-substituted oximes, hydroxy-lamines, and N-oxides, respectively [93-94]. Secondary alcohols are selectively oxidised to corresponding ketones. From primary alcohols, aldehydes or carboxylic acids are produced, under low or high conversion conditions, respectively. It is noteworthy that the oxidation of methanol is sufficiently slow, to allow its use as the solvent of choice for most reactions. The rate of oxidation of primary and secondary alcohols decreases with increasing chain length and number of substituents. The OH group position is important as well. 2-Pentanol reacts 13 times faster than 3-isomer [93]. 

Primary amines Primary alcohols Aldehydes Methyl ethers Carboxylic acids Thiols... 

By oxidation of aldehydes and primary alcohols. Aldehydes can be oxidized to carboxylic acids with mild oxidizing agents such as Ag(NH3)2" HO (Section 16.12B). Primary alcohols can be oxidized with KMn04. Aldehydes and primary alcohols are oxidized to carboxylic acids with chromic acid (H2Cr04) in aqueous acetone (the Jones oxidation Section 12.4C). 

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