Alcohols

Alcohol is referenced by the name of its parent alkane. -a nol and a number designating the position of the -OH group on the chain are used in place of the -ane suffix of the parent hydrocarbon chain. Whereas this saturated carbon atom is joined to a hydroxyl (-OH) group, alcohol is created.

Alkanols, which have the general formula R-OH, is the generic name for alcohol according to the IUPAC (International Union of Pure and Applied Chemistry) Nomenclature.

Alcohols occur frequently in nature, with ethyl alcohol (ethanol), the primary component of alcoholic beverages, being the most well-known. In the homologous sequence of alcohols, methanol (CH₃OH) and ethanol (CH₃CH₂OH) are the first two compounds.

Classification of Alcohols

Alcohol can be divided into three categories based on how many hydroxyl groups are linked, 

• Monohybrid Alcohol: The standard formula for monohydric alcohols is C_nH_2n+1OH, where n is 1, 2, etc. They can alternatively be expressed as R-OH, where R stands for an alkyl group. They have a single -OH group.  An example is CH₃CH₂-OH.
• Dihybrid Alcohol: The standard formula for dihydric alcohols is (CH₂)_n(OH)₂, where n is 2, 3, 4, etc. We call them “glycols” because of their sweet flavor. We can categorize them as α, β, ϒ…..ω-glycols, etc. depending on the relative positions of the two hydroxyl groups. They have two -OH groups. An example is 1,2-Ethanediol.
• Trihybrid Alcohol: Trihydric alcohols have the standard formula (CH₂)_n(OH)₃, where n is 3, 4, 5, etc. There is no overall nomenclature guideline in this system. The IUPAC has only one rule. These trihydric alcohols are known as Alkanethiols in the IUPAC classification system. We denote the position of the -OH group by Arabic numerals.

Alcohols are divided into three categories based on the number of carbon atoms that are bound to the carbon that is in direct contact with the -OH group. 

• In Primary Alcohol, one carbon atom is linked directly. 
• In Secondary Alcohol, two carbon atom is linked directly. 
• In Tertiary Alcohol, three carbon atom is linked directly.  

IUPAC Nomenclature for Alcohols

Common names for alcohols with one to four carbon atoms typically include the word alcohol after the name of the alkyl group. 

The International Union of Pure and Applied Chemistry (IUPAC) states that. -anol replaces the parent hydrocarbon chain’s -ane suffix. Basic IUPAC guidelines for identifying alcohol include:

• The parent compound is decided based on the length of the longest continuous chain (LCC) of carbon atoms bearing the -OH group.

• The chain is numbered from the end closest to the -OH group, with the -OH group occupying the lowest position in the chain (lowest locant rule).

• The parent hydrocarbon’s alkane chain’s -ane suffix is changed to -anol, and the name of the parent hydrocarbon is appended with the number denoting the position of the OH group.

• 4. The carbon atom that is linked to the -OH group is referred to as C1 in cyclic alcohols, but the number 1 is not present in the nomenclature. Substituents are given names and numbers, as with alkanes.

• Suffixes like “diol” and “triol” are used when there are many -OH groups present in a single molecule (polyhydroxy alcohols). When naming polyhydroxy alcohols, the parent alkane’s final ‘-e’ is maintained.

• The absolute configuration appears at the start of the name if the OH group is linked to a chiral centre. Additionally, the E and Z configuration should be addressed when necessary, if there is a double bond.

• The ring is numbered clockwise or anticlockwise depending on which orientation provides the following substituent for the lower number when other groups are present.

Common System: Alkyl alcohol is the common name for monohydric alcohols. After the name of the alkyl group is present in the molecule, we can add the name alcohol to get their names. For instance, the CH3-OH molecule combines an alcohol group and one methyl group. As a result, we refer to it as methyl alcohol.

In the standard method, we simply append the word “Glycol” to the end of the name of the alkene to name the – glycols. The names of the – glycols, in contrast, are the same as those of the equivalent polyethylene glycols.

Alcohols Ethers and Phenols are the categories of organic compounds. These compounds are used extensively in a variety of household businesses. Alcohol is created when the hydroxyl (-OH) group forms a bond with the saturated carbon atom. Ether is created when alcohol is dehydrated. These are the classes of organic compounds that are used in a variety of residential and industrial environments.