Alcohols - Carboxyl / Alfa Chemistry

Introduction

Alcohols, characterized by the presence of the hydroxyl (-OH) functional group attached to a carbon atom, are a significant class of organic compounds. With the molecular formula ROH, where R typically represents an alkyl group, they exhibit unique properties and reactivity crucial to industrial, pharmaceutical, and biochemical processes. Fig. 1 shows the structure of ethanol, the most common alcohol compound.

As a leading chemical supplier, Alfa Chemistry offers a diverse range of alcohols, available in quantities from grams to kilograms, tailored to various applications.

Fig. 1. Structure of ethanol.

Structure and Classification of Alcohols

Expressed by the general formula R-OH, if R denotes an alkyl group, this structure represents the sp3 hybridization (Fig. 2) of the oxygen atoms within the hydroxyl group. For instance, in methanol (CH3OH), the oxygen atom exhibits sp3 hybridization, forming two σ-bonds with hydrogen and carbon atoms, while two lone pairs of electrons occupy the remaining sp3 hybridized orbitals. Notably, when the hydroxyl group is bonded to a double- or triple-bonded carbon atom, the oxygen atom forms a σ-bond with the sp2 or sp hybridized orbital of carbon.

Fig. 2. Illustration of sp³ hybridization.

Alcohols can be classified based on either the number of hydroxyl groups within the molecule or the type of carbon atom to which the hydroxyl groups are bonded.

Based on the number of hydroxyl group contained in the molecule, alcohols are categorized as monohydric, dihydric, or polyhydric, depending on whether they contain one, two, or more than two hydroxyl groups, respectively.
Based on whether the hydroxyl group is attached to a primary, secondary, or tertiary carbon atom, respectively, alcohols are termed primary alcohol, secondary alcohol, or tertiary alcohol (Fig. 3).

Fig. 3. Structures of primary, secondary, and tertiary alcohols.

Representative Reactions

Alcohols serve as the basis for a wide range of organic synthesis and functional group transformations in organic chemistry. A few representative reactions of alcohols are briefly listed here.

Oxidation: Alcohols can be oxidized to form aldehydes, ketones, or carboxylic acids, depending on the conditions and the type of alcohol. For example, primary alcohols can be oxidized to aldehydes and then further oxidized to carboxylic acids; Secondary alcohols are oxidized to ketones; Tertiary alcohols are not easily oxidized.
Dehydration: Alcohols can undergo dehydration reactions to form alkenes and water. This typically occurs under acidic conditions, where a proton is removed from the alcohol molecule, leading to the formation of a carbocation intermediate, followed by the loss of a water molecule to form the alkene.
Substitution Reactions: Alcohols can undergo substitution reactions, particularly under acidic or basic conditions. For example, under acidic conditions, alcohols can react with hydrogen halides (e.g., HCl, HBr) to form alkyl halides (chlorides, bromides). Under basic conditions, they can react with alkyl halides via an SN2 mechanism to form ethers.

Applications

Alfa Chemistry recognizes the multifaceted applications of alcohols across diverse industries. Below list a few examples of the wide-ranging applications of alcohols across different industries.

In the pharmaceutical industry, alcohols serve as solvents, intermediates, and reagents in drug synthesis. For example, ethanol finds extensive use in the formulation of medications and pharmaceutical preparations.
In the cosmetic industry, alcohols function as solvents, preservatives, and viscosity modifiers in skincare products, perfumes, and hair care formulations.
In the food industry, alcohols play a crucial role as key components in various beverages. For instance, ethanol serves as a primary ingredient in alcoholic beverages like beer, wine, and spirits. Moreover, it serves as a versatile solvent in food extracts, flavorings, and food colorings.

Alfa Chemistry provides various of alcohols to our customers from grams to kilograms. We can also customize synthesis according to customers' requirements. Please feel free to contact us for more information.