Question

1. What will be the odor produced when ethyl alcohol reacts with acetyl chloride? 2. What will be the odor produced when n-butyl alcohol reacts with acetyl chloride? 3. What will be the odor produced when glycerol reacts with acetyl chloride? 4. What will be the odor produced when benzyl alcohol reacts with acetyl chloride? 5. What will be the odor produced when benzyl alcohol reacts with acetyl chloride?

Answer 1

Ethanol and water are the main components of most alcoholic beverages, although in some very sweet liqueurs the sugar content can be higher than the ethanol content. Ethanol (CAS Reg. No. 64–17–5) is present in alcoholic beverages as a consequence of the fermentation of carbohydrates with yeast. It can also be manufactured from ethylene obtained from cracked petroleum hydrocarbons. The alcoholic beverage industry has generally agreed not to use synthetic ethanol manufactured from ethylene for the production of alcoholic beverages, due to the presence of impurities. In order to determine whether synthetic ethanol has been used to fortify products, the low 14C content of synthetic ethanol, as compared to fermentation ethanol produced from carbohydrates, can be used as a marker in control analyses (McWeeny & Bates, 1980).

Some physical and chemical characteristics of anhydrous ethanol are as follows (Windholz, 1983):

Description: Clear, colourless liquid

Boiling-point: 78.5°C

Melting-point: −114.1 °C

Density: Image Eq05a_01.jpg 0.789

It is widely used in the laboratory and in industry as a solvent for resins, fats and oils. It also finds use in the manufacture of denatured alcohol, in pharmaceuticals and cosmetics (lotions, perfumes), as a chemical intermediate and as a fuel, either alone or in mixtures with gasoline.

Beer, wine and spirits also contain volatile and nonvolatile flavour compounds. Although the term ‘volatile compound’ is rather diffuse, most of the compounds that occur in alcoholic beverages can be grouped according to whether they are distilled with alcohol and steam, or not. Volatile compounds include aliphatic carbonyl compounds, alcohols, monocarboxylic acids and their esters, nitrogen- and sulphur-containing compounds, hydrocarbons, terpenic compounds, and heterocyclic and aromatic compounds. Nonvolatile extracts of alcoholic beverages comprise unfermented sugars, di- and tribasic carboxylic acids, colouring substances, tannic and polyphenolic substances, and inorganic salts. The flavour composition of alcoholic beverages has been described in detail in several reviews (Suomalainen & Nykänen, 1970; Amerine et al., 1972; Nykänen & Suomalainen, 1983), and a recent review on the compounds occurring in distilled alcoholic beverages is available (ter Heide, 1986). The volatile compounds of alcoholic beverages and distillates generally originate from three sources: raw materials, fermentation and the wooden casks in which they are matured (Jouret & Puech, 1975).

Answer 2

Answers are given below.

Explanation:

1.  When alcohols are heated with an acid halide, the hydrogen of −OH group

    is replaced by acyl group $\[(RCO-)\]$ and an ester is formed.

                   $\[C{{H}_{3}}COCl+HO{{C}_{2}}{{H}_{6}}\to C{{H}_{3}}COO{{C}_{2}}{{H}_{5}}+HCl\]$

    $\[Acetyl\text{ }chloride~~~~~Ethyl\text{ }alcohol~~~~~Ethyl\text{ }acetate\]$                    

    This reaction is known as Acylation.

2. Carboxylic acid chlorides also react with alcohols to form esters by

    nucleophilic acyl substitution. This equation shown in the image

    describes the preparation of t-butyl acetate. It is made from acetyl

    chloride and t-butyl alcohol. Pyridine, $\[{{C}_{5}}{{H}_{5}}N,\]$ which is an organic base,

    is added as a catalyst and an "acid trap" to react with the   that is formed

    along with the $\[HCl\]$ ester.

    Refer the attached image for the reaction.

3. When glycerol reacts with acetyl chloride, then glycerol monoacetate,

    glycerol diacetate, glycerol triacetate are formed.

    Refer the attached image for the reaction.

4. Benzyl acetate is an organic ester with the molecular formula $\[{{C}_{9}}{{H}_{10}}{{O}_{2}}\]$. It

   is formed by the condensation of benzyl alcohol and acetyl chloride.

   $\[{{C}_{6}}{{H}_{5}}C{{H}_{2}}OH+C{{H}_{3}}COCl\to {{C}_{6}}{{H}_{5}}OCOC{{H}_{3}}\]$