MPharm PHA111 Functional Group Chemistry 3

Phenols are planar molecules with a shorter C-O bond distance compared to aliphatic alcohols, making them more reactive. They have a special type of hydrogen bonding that makes them more soluble in water than other molecules of similar size.

Phenols have a higher melting and boiling point than aliphatic alcohols because of their ability to form stronger hydrogen bonds with other phenol molecules and with water.

Phenols are more acidic than aliphatic alcohols because the phenoxide ion is stabilized by resonance, making it easier to lose a hydrogen ion.

Epinephrine (adrenaline) is a biologically important phenol that plays a crucial role in the 'fight or flight' response, increasing heart rate and triggering other physiological events.

Epinephrine is synthesized from tyrosine by way of DOPA, showcasing its connection to amino acids and its biological importance.

A chemical reaction where an alcohol reacts with an acid to form an ester and water. The reaction is reversible and is catalyzed by an acid (like sulfuric acid).

The process of gaining oxygen atoms or losing hydrogen atoms in a molecule. For example, an alcohol can be oxidized to an aldehyde or a ketone.

Functional groups containing a carbon atom double-bonded to an oxygen atom and single-bonded to a hydrogen atom. They are generally found in aldehydes.

Functional groups containing a carbon atom double-bonded to an oxygen atom and single-bonded to two other carbon atoms. They are generally found in ketones.

An enzyme that converts alcohol into an aldehyde. It's involved in the body's metabolism of alcohol.

Functional groups containing a carbon atom double-bonded to an oxygen atom and single-bonded to a hydroxyl group (OH). They are generally found in carboxylic acids.

A reaction used to convert alcohols into haloalkanes (alkyl halides). This involves replacing the hydroxyl group (-OH) with a halogen atom (like chlorine, bromine, or iodine).

A type of reaction where a substance loses electrons and gains a positive charge (oxidation). It essentially removes electrons.

Functional groups containing a carbon atom double-bonded to an oxygen atom and single-bonded to an OR group (where R is an alkyl group). They are generally found in esters.

A chemical process that involves the addition of hydrogen atoms (H-) to a molecule, often reducing the number of carbon-oxygen double bonds.

A special type of oxidation reaction in the body where alcohol is sequentially converted to an aldehyde and then an acid. The second step is inhibited by disulfiram (Antabuse), a drug used in alcohol aversion therapy.

The process of losing oxygen atoms or gaining hydrogen atoms in a molecule. The opposite of oxidation.

Compounds that can be prepared by reducing carbonyl-containing compounds like aldehydes, ketones, esters, and carboxylic acids.

A class of organic compounds characterized by the presence of a halogen atom (like chlorine, bromine, or iodine) bonded to a carbon atom.

A reducing agent commonly used to reduce aldehydes and ketones to primary and secondary alcohols, respectively.

A stronger reducing agent used to reduce aldehydes, ketones, esters, and carboxylic acids to primary and secondary alcohols, and primary alcohols to alkanes.

A type of chemical reaction where an alcohol reacts with sodium metal, resulting in the formation of an alkoxide and the release of hydrogen gas. This is also an example of a redox reaction.

Alcohols can be burned completely in oxygen to produce carbon dioxide, water, and heat. This is an exothermic reaction.

Alcohols are organic compounds containing a hydroxyl (-OH) group attached to a carbon atom. They can be saturated or unsaturated and are classified as primary, secondary, or tertiary based on the number of carbon atoms directly attached to the carbon bearing the hydroxyl group.

Alcohols can form hydrogen bonds due to the presence of the hydroxyl group. These interactions lead to relatively higher boiling points compared to comparable hydrocarbons.

The acidity of alcohols is measured by their pKa values. The pKa values of alcohols are generally around 15-18, indicating that they are weak acids.

The acidity of alcohols is influenced by the presence of electron-donating or electron-withdrawing groups. Electron-donating groups, such as alkyl groups, decrease acidity (higher pKa), while electron-withdrawing groups, such as halogens, increase acidity (lower pKa).

Phenols are aromatic compounds containing a hydroxyl group directly attached to a benzene ring. They exhibit significantly higher acidity (pKa ~10) compared to aliphatic alcohols due to resonance stabilization of the phenoxide ion.

Methanol is the simplest alcohol and is highly toxic. Its consumption can lead to blindness and even death.

Ethanol, the alcohol found in alcoholic beverages, is produced through fermentation of sugars by yeast. It is considered less toxic than methanol but still poses health risks.

The main methods for preparing more complex alcohols include hydration of alkenes, hydrolysis of alkyl halides, and reduction of carbonyl compounds.

Hydration of alkenes involves the addition of water to an alkene in the presence of an acid catalyst. The reaction proceeds via a carbocation intermediate.

Hydrolysis of alkyl halides involves the reaction of an alkyl halide with water in the presence of a base. This reaction proceeds via an SN1 or SN2 mechanism, depending on the conditions and structure of the alkyl halide.

Reduction of carbonyl compounds involves the conversion of a carbonyl compound to a corresponding alcohol using reducing agents such as lithium aluminum hydride (LiAlH4) or sodium borohydride (NaBH4).

Nucleophilic substitution reactions involve the replacement of a leaving group by a nucleophile. In the context of alcohols, the hydroxyl group can act as a leaving group after protonation, allowing for the formation of alkyl halides.

The reactivity of alcohols and alkyl halides in nucleophilic substitution reactions is influenced by several factors, including the nature of the leaving group, the strength of the nucleophile, and steric hindrance.

Alcohols undergo various reactions, including oxidation, dehydration, and esterification. The specific reaction depends on the structure of the alcohol and the reaction conditions.

Haloalkanes are organic compounds containing a carbon-halogen (C-X) bond. They are also known as alkyl halides. Halogens are more electronegative than carbon, leading to a polar C-X bond. The carbon atom has a partial positive charge (δ+), making it an electrophile.

The reactivity of haloalkanes comes from the electrophilic carbon, which attracts nucleophiles (electron-rich species). When a nucleophile attacks, the halogen acts as a "leaving group", taking its electron pair with it, resulting in a substitution reaction.

Haloalkanes are used as anesthetics. Diethyl ether was historically used but was replaced by halothanes due to safety concerns. Halothanes, like halothane, enthrane, and penthrane, are safer and more effective.

Due to the polar C-X bond, haloalkanes have higher boiling points than alkanes of comparable size and shape. The higher polarizability of the C-X bond contributes to stronger intermolecular forces.

Liquid haloalkanes are generally denser than hydrocarbons of similar molecular weight. Bromoalkanes and iodoalkanes are denser than water. Di- and polyhalogenated alkanes have even higher densities.

Haloalkanes can be synthesized through various methods, including free radical substitution of alkanes, electrophilic addition of HX to alkenes, halogenation of alkenes or alkynes, and halogenation of alcohols.

Haloalkanes undergo nucleophilic substitution, a reaction where a nucleophile replaces the halogen atom attached to the carbon. The nucleophile attacks the electrophilic carbon. This reaction can follow two different mechanisms.

The electrophilic carbon atom in haloalkanes makes them ideal for nucleophilic substitution reactions. Nucleophiles are electron-rich species that attack the partially positive carbon atom, leading to the substitution of the halogen.

Haloalkanes play a diverse role in various industries. They are used as solvents, refrigerants, pesticides, and in the synthesis of other organic compounds. Their unique reactivity makes them versatile building blocks in organic chemistry.

Haloalkanes find applications in agriculture as pesticides and herbicides. Their ability to kill insects and weeds makes them useful in controlling unwanted organisms. This is due to their interaction with enzyme systems and their ability to disrupt biological processes.