LECTURELECTURE

CLASSIFICATION, STRUCTURE, CLASSIFICATION, STRUCTURE, NOMENCLATURE AND NOMENCLATURE AND

PROPERTIES OF ORGANIC PROPERTIES OF ORGANIC COMPOUNDS. COMPOUNDS.

TYPES OF CHEMICAL TYPES OF CHEMICAL REACTIONSREACTIONS

Lecturer: Iryna R. BekusLecturer: Iryna R. Bekus

Organic Chemistry Organic Chemistry – – tthe chemistry of he chemistry of the hydrocarbons and their derivatives; the hydrocarbons and their derivatives; the chemistry of carbon compounds.the chemistry of carbon compounds.

Bioorganic Chemistry Bioorganic Chemistry was study was study structure and properties of compounds, structure and properties of compounds, which are in human body. which are in human body.

Such as: Such as: proteins, lipids, hormones, carbohydrates, proteins, lipids, hormones, carbohydrates,

vitamins, enzyme, fatsvitamins, enzyme, fats, at el., at el.

CLASSIFICATIONCLASSIFICATION By structure of carbon chain:By structure of carbon chain:

Acyclic Acyclic — — compounds, that don’t contain any compounds, that don’t contain any cycle in their molecules. cycle in their molecules. SaturatedSaturated — compounds that contain only — compounds that contain only --bonds and nbonds and nоо - bonds (simple – C – C – - bonds (simple – C – C – bonds).bonds).AlkanesAlkanes — saturated hydrocarbons that contain — saturated hydrocarbons that contain only – C – C – and – C – H – only – C – C – and – C – H – bonds. bonds.UnsaturatedUnsaturated — compounds that contain — compounds that contain --bonds and bonds and - bonds (double bonds (– C = C –) - bonds (double bonds (– C = C –) or triple (– C or triple (– C C – ) bonds, and simple – C – C – ) bonds, and simple – C – C – bonds).C – bonds).

AlkenesAlkenes — unsaturated hydrocarbons th— unsaturated hydrocarbons thааt t contain only one – C – C – double bond contain only one – C – C – double bond (– C = C –).(– C = C –).DieneDiene — — unsaturatedunsaturated compounds compounds ththааt contain t contain two double two double – C – C – – C – C – bonds.bonds.AlkynesAlkynes — — unsaturatedunsaturated hydrocarbons hydrocarbons ththааt t contain – C – C – contain – C – C – triple bond triple bond (– C (– C C – ) C – )..CyclicCyclic — organic compounds — organic compounds ththааt contain any t contain any cycle in its molecules.cycle in its molecules.

CarbocyclicCarbocyclic - hydrocarbons containing - hydrocarbons containing аа cycle cycle that consists of only Carbon atoms.that consists of only Carbon atoms.CycloalkanesCycloalkanes — saturated hydrocarbons — saturated hydrocarbons containing containing аа Carbon cycle. Carbon cycle.CycloalkenesCycloalkenes — ansaturated hydrocarbons — ansaturated hydrocarbons containing containing аа Carbon cycle. Carbon cycle.ArenesArenes — aromatic compounds th— aromatic compounds thааt contain t contain benzoic ring.benzoic ring.HeterocyclicHeterocyclic - - organic compounds organic compounds ththааt contain t contain cycle between atoms of Carbon and other cycle between atoms of Carbon and other elements (S, O, N).elements (S, O, N).

Functional GroupFunctional Group is any is any part of an organic part of an organic compound, which is not compound, which is not аа carbon-hydrogen or carbon-hydrogen or carbon-carbon single bon.carbon-carbon single bon.

By functional groups:By functional groups:

There are mono-, poly- and heterofunctional group in the structure of organic compounds:

Monofunctional group – contains only 1 functional group.

C2H5—OH Polyfunctional group – contains several similar functional group. H2C

CH

H2C

OH

OH

OH

Heterofunctional group – contains several different functional group.

OH

C

O

H

NOMENCLATURENOMENCLATURE Common (trivial)Common (trivial) International International ((IUPAC – IUPAC –

International Union of Pure International Union of Pure and Applied Chemistryand Applied Chemistry) ) system of nomenclature was first system of nomenclature was first introduced in 1947.introduced in 1947.

General rules for IUPAC nomenclature:General rules for IUPAC nomenclature: The The IUPACIUPAC name of any organic compound name of any organic compound

essentially consists of three parts: essentially consists of three parts:

1.1. word root; word root;

2.2. suffix; suffix;

3.3. prefix.prefix. Thus, Thus, аа complete IUPAC name of an organic complete IUPAC name of an organic

compound consists of the following parts:compound consists of the following parts:

• Secondary prefix + Primary prefix + Word Secondary prefix + Primary prefix + Word root + Primary suffix + Secondary suffixroot + Primary suffix + Secondary suffix

SUFFIXSUFFIX

There are two types of suffixes:There are two types of suffixes:Primary suffix.Primary suffix. АА primary suffix is always primary suffix is always added to the word root to indicate whether the added to the word root to indicate whether the carbon chain is saturated carbon chain is saturated ооr unsaturated. The r unsaturated. The three basic primary suffixes are given below:three basic primary suffixes are given below:

Secondary suffix.Secondary suffix. АА secondary suffix is then added secondary suffix is then added to the primary suffix to indicate the nature of the to the primary suffix to indicate the nature of the functional group present in the organic compound. functional group present in the organic compound. Secondary suffixes of some important functional Secondary suffixes of some important functional groups are given below:groups are given below:

PREFIXPREFIX

There are two types of prefixes:There are two types of prefixes:

Primary prefix.Primary prefix. АА primary prefix is primary prefix is used simply to distinguish cyclic used simply to distinguish cyclic from acyclic compounds.from acyclic compounds.

For example, in case of carbocyclic For example, in case of carbocyclic compounds, compounds, аа primary prefix, cyclo primary prefix, cyclo is used immediately before the is used immediately before the word root. Thus:word root. Thus:

CyclopentaneCyclopentane

Secondary prefix.Secondary prefix. In IUPAC system of nomenclature, In IUPAC system of nomenclature, certain groups are not considered as functional certain groups are not considered as functional groups but instead are treated as substituents. These groups but instead are treated as substituents. These are called secondary prefixes.are called secondary prefixes.

Complete structural formula:

C C C

H

H

H

H

H

H

H

C

H

H

H

C

C

C

C

C

C

H

H

H H

H

H

H

H

HHH

H

hexane butane

Shorten structural formula:

CH3—CH2—CH2—CH3

H2C

H2C

H2C

CH2

CH2

CH2

butane

hexane

Types of organic reactions.Types of organic reactions.All the organic reactions can be broadly All the organic reactions can be broadly

classified into the following four types: classified into the following four types:

(a) substitution reactions, (a) substitution reactions, (b) addition reactions, (b) addition reactions, (c) elimination reactions, (c) elimination reactions, (d) rearrangement reactions.(d) rearrangement reactions.

(I) (I) Substitution reactions which are brought about by Substitution reactions which are brought about by nucleophiles are called nucleophiles are called nucleophilic substitution nucleophilic substitution reactions:reactions:

CHCH33OH + CHOH + CH

33COOH COOH CH CH33COOCHCOOCH

33 + H + H22OO

((II) II) Substitution reactions which are brought about by Substitution reactions which are brought about by electropholes are called electropholes are called electrophilic substitution electrophilic substitution reactionsreactions::

(III) (III) SubstitutionSubstitution reactions brought about by free reactions brought about by free radicals are called radicals are called free free radical substitution radical substitution reactionsreactions::

CHCH44 +Cl +Cl2 2 → → CHCH33Cl +HClCl +HCl

Addition reactionsAddition reactionsAddition reactions are of the following three types:Addition reactions are of the following three types:

Addition reactions brought about by nucleophiles are called Addition reactions brought about by nucleophiles are called nucleophilic addition reactionsnucleophilic addition reactions::

Addition reactions brought about by electrophiles are called Addition reactions brought about by electrophiles are called electrophilic addition reactionselectrophilic addition reactions..

Addition reactions brought about by free radicals are called Addition reactions brought about by free radicals are called free radical addition reactionsfree radical addition reactions..

Elimination reactions.Elimination reactions. An elimination reaction is An elimination reaction is one that involves the loss of two atoms orgroups of one that involves the loss of two atoms orgroups of atoms form the same or adjacent atoms of a atoms form the same or adjacent atoms of a substance leading the formation of a multiple substance leading the formation of a multiple (double or triple) bond: (double or triple) bond:

These are of two types:These are of two types: -Elimination reactions-Elimination reactions.. -Elimination reactions.-Elimination reactions.

Reactions involving the migration of an atom or a group from Reactions involving the migration of an atom or a group from one atom to another within the same molecule are called one atom to another within the same molecule are called rearrangement reactions.rearrangement reactions.

OxidationOxidation — — аа net decrease in the number of net decrease in the number of bonds to hydrogen or electropositive element, or bonds to hydrogen or electropositive element, or аа

net increase in the number of bonds to net increase in the number of bonds to electronegative elements. electronegative elements. АА net loss of electrons. net loss of electrons.

Reduction Reduction — — аа net increase in the number of net increase in the number of bonds to hydrogen or electropositive element, or bonds to hydrogen or electropositive element, or аа net decrease in the number of bonds to net decrease in the number of bonds to electronegative elements. electronegative elements. АА net gains electrons. net gains electrons.

ALCOHOL

In chemistry, an alcohol is an organic compound in which the hydroxyl functional group (-OH) is bound

to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three

other atoms.

Systematic names

In the IUPAC system, the name of the alkane chain loses the terminal "e" and adds "ol", e.g.,

"methanol" and "ethanol“

Classification of alcohols

Alcohols with one hydroxyl group - monohydric alcohol

Alcohols with two hydroxyl groups - dihydric alcohol

Alcohols with three hydroxyl groups - trihydric alcohols

Alcohols with four or more hydroxyl groups - polyhydric alcohols

The saturated monohydric alcohols have the general formula CnH2n+1OH or ROH. Their functional group

is -OH. They can be further classified into:

1) Primary Alcohol

Here the carbon atom bearing the hydroxyl group is attached to just one other carbon atom.

2) Secondary AlcoholHere the carbon atom bearing the hydroxyl group is attached to two other carbon atoms.

3)Tertiary Alcohol

Here the carbon atom bearing the hydroxyl group is attached to three other carbon atoms.

Carbonyl GroupCarbonyl Group

Carbon atom joined to oxygen by a Carbon atom joined to oxygen by a double bonddouble bond

KetonesKetones

Aldehydes                         

                                                                                    

AldehydesAldehydes

Comes from alcohol dehydrogenationComes from alcohol dehydrogenation Obtained by removing of a hydrogen Obtained by removing of a hydrogen

from an alcoholfrom an alcohol

                                                                                                            

Aldehydes Aldehydes

Both common and IUPAC names Both common and IUPAC names frequently usedfrequently used

Common names from acids from Common names from acids from which aldehydes can be convertedwhich aldehydes can be converted

                                                                                                                      

AldehydesAldehydes IUPACIUPAC Longest chain with aldehydeLongest chain with aldehyde Drop “e” and add “-al”Drop “e” and add “-al”

• Acetaldehyde Acetaldehyde PropionaldehydePropionaldehyde

Phenylethanal

KetonesKetones

Naming:Naming:• Drop “e”, add “-one”Drop “e”, add “-one”• Many common namesMany common names• Simplest is 3 carbons Simplest is 3 carbons

C. name: acetoneC. name: acetone IUPAC: propanoneIUPAC: propanone

                                                                                                                                            

Physical Properties of Aldehydes Physical Properties of Aldehydes and Ketonesand Ketones

Carbon-oxygen double bond is very polarCarbon-oxygen double bond is very polar• Affects boiling pointsAffects boiling points• More than ethers (C-O bonds)More than ethers (C-O bonds)• Less than alcohols (C-OH bonds)Less than alcohols (C-OH bonds)

OdorsOdors• Low aldehydes very pungentLow aldehydes very pungent• High aldehydes pleasant odors (perfumes)High aldehydes pleasant odors (perfumes)

Solubility Solubility • Similar to alcohols and ethersSimilar to alcohols and ethers• Soluble up to about 4 carbonsSoluble up to about 4 carbons• Insoluble after thatInsoluble after that

Preparation of AldehydesPreparation of Aldehydes Oxidation Oxidation

                                                                                                                                            

                        

                                                                    

                  

Hydration of alkynes (Kucherov reaction). Reaction occurs by way of an enol

intermediate formed by Markovnikov addition of water to the triple bond.

Oxosynthesis. Oxosynthesis.

Interaction of alkenes with carbone (II) Interaction of alkenes with carbone (II) oxide, at the higher temperature, oxide, at the higher temperature, pressure and presence of catalyst. pressure and presence of catalyst.

Preparation of KetonesPreparation of Ketones OxidationOxidation

                                            

                

                                                

                

Chemical Properties of Aldehydes Chemical Properties of Aldehydes and Ketonesand Ketones

Both undergo combustion reactionsBoth undergo combustion reactions OxidationOxidation

• Aldehydes can be oxidized, ketones Aldehydes can be oxidized, ketones can’tcan’t

• See See Tollen’s reagentTollen’s reagent Benedict’s reagentBenedict’s reagent Fehling’s reagentFehling’s reagent

  

Reactions of aldehyde oxidationReactions of aldehyde oxidation

With Tollens’ reagent – “silver With Tollens’ reagent – “silver mirror” reaction.mirror” reaction.

With Fehling reagent: after heating red precipitate of copper (I) oxide formed.

Chemical Properties of Aldehydes Chemical Properties of Aldehydes and Ketonesand Ketones

Reduction Reduction • Variety of agents can reduce aldehydes Variety of agents can reduce aldehydes

and ketones to alcoholsand ketones to alcohols

                                                                      

                  

                                                          

                

                                                                                                          

                      

Chemical Properties of Aldehydes Chemical Properties of Aldehydes and Ketonesand Ketones

HydrationHydration• Formaldehyde dissolves readily in waterFormaldehyde dissolves readily in water• Acetaldehyde somewhat alsoAcetaldehyde somewhat also

Form Form hydrateshydrates

                                                                

                  

                                                                       

Chemical Properties of Aldehydes Chemical Properties of Aldehydes and Ketonesand Ketones

Addition of Alcohols to Carbonyl Addition of Alcohols to Carbonyl GroupsGroups• HemiacetalHemiacetal

Aldehyde + alcoholAldehyde + alcohol

• Hemiketal Hemiketal Ketone + alcoholKetone + alcohol

                                                            

                  

                                                            

                  

Chemical Properties of Aldehydes Chemical Properties of Aldehydes and Ketonesand Ketones

Hemiacetals + HCl = acetalHemiacetals + HCl = acetal

Hemiketal + HCl = ketalHemiketal + HCl = ketal

                                                                                                    

                      

Thank you for attentionThank you for attention