Organic chemistry Notes

 Page 1


Study Guide: CHEM110  - Organic Chemistry 1
CHEM 110
Module 3 Organic Chemistry
Module Notes
Page 2


Study Guide: CHEM110  - Organic Chemistry 1
CHEM 110
Module 3 Organic Chemistry
Module Notes
Study Guide: CHEM110  - Organic Chemistry 2
T T T Ta a a ab b b bl l l le e e e    o o o of f f f    C C C Co o o on n n nt t t te e e en n n nt t t ts s s s
Topic 3A – Introduction ................................................................... 1
Topic 3B - Bonding in carbon compounds.............................................. 7
Topic 3C – Alkanes .......................................................................16
Topic 3D - Alkenes and Alkynes........................................................31
Topic 3E - Aromatic compounds........................................................49
Topic 3F Alkyl halides....................................................................61
Topic 3G – Alcohols ......................................................................69
Topic 3H – Amines........................................................................80
Topic 3I - Aldehydes and Ketones ......................................................88
Topic 3J - Carboxylic acids and their derivatives.....................................96
Page 3


Study Guide: CHEM110  - Organic Chemistry 1
CHEM 110
Module 3 Organic Chemistry
Module Notes
Study Guide: CHEM110  - Organic Chemistry 2
T T T Ta a a ab b b bl l l le e e e    o o o of f f f    C C C Co o o on n n nt t t te e e en n n nt t t ts s s s
Topic 3A – Introduction ................................................................... 1
Topic 3B - Bonding in carbon compounds.............................................. 7
Topic 3C – Alkanes .......................................................................16
Topic 3D - Alkenes and Alkynes........................................................31
Topic 3E - Aromatic compounds........................................................49
Topic 3F Alkyl halides....................................................................61
Topic 3G – Alcohols ......................................................................69
Topic 3H – Amines........................................................................80
Topic 3I - Aldehydes and Ketones ......................................................88
Topic 3J - Carboxylic acids and their derivatives.....................................96
Study Guide: CHEM110  - Organic Chemistry 1
O O O Or r r rg g g ga a a an n n ni i i ic c c c
C C C Ch h h he e e em m m mi i i is s s st t t tr r r ry y y y
M M M Mo o o od d d du u u ul l l le e e e
3 3
3 3
Topic 3A – Introduction
K K K Ke e e ey y y y    q q q qu u u ue e e es s s st t t ti i i io o o on n n ns s s s
Why is carbon so special?  How is it that the vast majority of chemicals known
today are made from carbon (and other elements)?  Carbon chemistry is not
only omnipresent in our society but it is emphatically the basis of life itself.  In
this topic we introduce you to the long history of the subject "carbon
chemistry" or more widely known as "organic chemistry" as well as deal with
the principles for breaking down such a vast field of science into
understandable units.
O O O Ou u u ut t t tl l l li i i in n n ne e e e
The notes produced for the CHEM110 organic chemistry component of the unit
are based on sections of the book Introduction to Organic Chemistry, William
H. Brown (described as Brown in these notes). However, the Module notes do
not necessarily follow exactly the order given in the text. We will also refer to
both the Saunders  ChemOffice Web CD-ROM (included with the Brown text)
and the General Chemistry CD-ROM (included with your other main text,
Chemistry and Chemical Reactivity, Kotz and Treichel, 5
th
 edition). These CD-
ROM references are not essential to learn this course, but we highly
recommend their use to gain a better understanding of the principles involved.
Some topics have been expanded from these prescribed materials, and others
given lesser emphasis or even omitted. This reflects our philosophy regarding
the relative importance of the various aspects of organic chemistry to be
covered in the unit.
The ordering adopted is based on that which has been found to be successful in
teaching the internal unit.  This permits the introduction of new topics and
concepts to be used as a revision of earlier parts of the unit.  Nonetheless, the
endpoint arrived at is essentially the same as that of the prescribed text.
Page 4


Study Guide: CHEM110  - Organic Chemistry 1
CHEM 110
Module 3 Organic Chemistry
Module Notes
Study Guide: CHEM110  - Organic Chemistry 2
T T T Ta a a ab b b bl l l le e e e    o o o of f f f    C C C Co o o on n n nt t t te e e en n n nt t t ts s s s
Topic 3A – Introduction ................................................................... 1
Topic 3B - Bonding in carbon compounds.............................................. 7
Topic 3C – Alkanes .......................................................................16
Topic 3D - Alkenes and Alkynes........................................................31
Topic 3E - Aromatic compounds........................................................49
Topic 3F Alkyl halides....................................................................61
Topic 3G – Alcohols ......................................................................69
Topic 3H – Amines........................................................................80
Topic 3I - Aldehydes and Ketones ......................................................88
Topic 3J - Carboxylic acids and their derivatives.....................................96
Study Guide: CHEM110  - Organic Chemistry 1
O O O Or r r rg g g ga a a an n n ni i i ic c c c
C C C Ch h h he e e em m m mi i i is s s st t t tr r r ry y y y
M M M Mo o o od d d du u u ul l l le e e e
3 3
3 3
Topic 3A – Introduction
K K K Ke e e ey y y y    q q q qu u u ue e e es s s st t t ti i i io o o on n n ns s s s
Why is carbon so special?  How is it that the vast majority of chemicals known
today are made from carbon (and other elements)?  Carbon chemistry is not
only omnipresent in our society but it is emphatically the basis of life itself.  In
this topic we introduce you to the long history of the subject "carbon
chemistry" or more widely known as "organic chemistry" as well as deal with
the principles for breaking down such a vast field of science into
understandable units.
O O O Ou u u ut t t tl l l li i i in n n ne e e e
The notes produced for the CHEM110 organic chemistry component of the unit
are based on sections of the book Introduction to Organic Chemistry, William
H. Brown (described as Brown in these notes). However, the Module notes do
not necessarily follow exactly the order given in the text. We will also refer to
both the Saunders  ChemOffice Web CD-ROM (included with the Brown text)
and the General Chemistry CD-ROM (included with your other main text,
Chemistry and Chemical Reactivity, Kotz and Treichel, 5
th
 edition). These CD-
ROM references are not essential to learn this course, but we highly
recommend their use to gain a better understanding of the principles involved.
Some topics have been expanded from these prescribed materials, and others
given lesser emphasis or even omitted. This reflects our philosophy regarding
the relative importance of the various aspects of organic chemistry to be
covered in the unit.
The ordering adopted is based on that which has been found to be successful in
teaching the internal unit.  This permits the introduction of new topics and
concepts to be used as a revision of earlier parts of the unit.  Nonetheless, the
endpoint arrived at is essentially the same as that of the prescribed text.
Study Guide: CHEM110  - Organic Chemistry 2
I I I In n n n    t t t th h h he e e e    b b b be e e eg g g gi i i in n n nn n n ni i i in n n ng g g g. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .
Friedrich Wöhler expressed a view of organic chemistry with which some
newcomers to the discipline might have some sympathy. In a letter to Jons
Jacob Berzelius in 1835, he wrote:
"Organic Chemistry just now is enough to drive one mad.  It gives me the
impression of a primeval tropical forest, full of the most remarkable things; a
monstrous and boundless thicket, with no way of escape, into which one may
well dread to enter".
Berzelius in 1808 had been involved in the isolation and study of chemicals
derived from living sources; the view at the time was that such "organic"
substances as they were known could not be synthesised in the laboratory from
"inorganic" materials, because it was believed that a "vital force" which was
possessed only by living organisms was necessary to produce organic
compounds.
This "Vital Force Theory" was challenged by Wöhler in 1828 when he heated
the inorganic compound ammonium cyanate (NH
4
OCN) and obtained urea
which was recognised as being "organic" because it could be isolated from
urine.
A few years later August Kekulé assigned the modern definition of organic
chemistry - organic compounds are those containing carbon.
Likewise Leopold Gmelin in 1848 defined organic chemistry as “the chemistry
of the compounds of carbon which occur naturally”.  This definition is too
restrictive, however - although many organic compounds are of natural origin,
the great majority owe their existence to the endeavours of academic and
industrial chemists.  Some may only have been synthesised in milligram
quantities (or less!) whereas others are manufactured annually on the scale of
millions of tonnes.
And let us not forget that all living matter is constructed of a multitude of
(mainly very complex) organic chemicals and that life processes are the
reactions of these chemicals.
In 1848 Wöhler was to write:
“The Philosopher of Chemistry will draw the conclusion that the production of
all organic matters in our laboratories, in as much as they do not belong any
more to the organism, must be regarded not only as probable but as certain.  It
is true we do not know the methods by which this final result will be reached,
because the rudiments are unknown from which they are to be developed, but
we shall know them in time”.
A magnificent statement for 1848!
Wöhler indicated various target natural products, among them morphine:  80
years were to elapse before the structure of morphine was elucidated and a
further 20 years before its synthesis was achieved.
Page 5


Study Guide: CHEM110  - Organic Chemistry 1
CHEM 110
Module 3 Organic Chemistry
Module Notes
Study Guide: CHEM110  - Organic Chemistry 2
T T T Ta a a ab b b bl l l le e e e    o o o of f f f    C C C Co o o on n n nt t t te e e en n n nt t t ts s s s
Topic 3A – Introduction ................................................................... 1
Topic 3B - Bonding in carbon compounds.............................................. 7
Topic 3C – Alkanes .......................................................................16
Topic 3D - Alkenes and Alkynes........................................................31
Topic 3E - Aromatic compounds........................................................49
Topic 3F Alkyl halides....................................................................61
Topic 3G – Alcohols ......................................................................69
Topic 3H – Amines........................................................................80
Topic 3I - Aldehydes and Ketones ......................................................88
Topic 3J - Carboxylic acids and their derivatives.....................................96
Study Guide: CHEM110  - Organic Chemistry 1
O O O Or r r rg g g ga a a an n n ni i i ic c c c
C C C Ch h h he e e em m m mi i i is s s st t t tr r r ry y y y
M M M Mo o o od d d du u u ul l l le e e e
3 3
3 3
Topic 3A – Introduction
K K K Ke e e ey y y y    q q q qu u u ue e e es s s st t t ti i i io o o on n n ns s s s
Why is carbon so special?  How is it that the vast majority of chemicals known
today are made from carbon (and other elements)?  Carbon chemistry is not
only omnipresent in our society but it is emphatically the basis of life itself.  In
this topic we introduce you to the long history of the subject "carbon
chemistry" or more widely known as "organic chemistry" as well as deal with
the principles for breaking down such a vast field of science into
understandable units.
O O O Ou u u ut t t tl l l li i i in n n ne e e e
The notes produced for the CHEM110 organic chemistry component of the unit
are based on sections of the book Introduction to Organic Chemistry, William
H. Brown (described as Brown in these notes). However, the Module notes do
not necessarily follow exactly the order given in the text. We will also refer to
both the Saunders  ChemOffice Web CD-ROM (included with the Brown text)
and the General Chemistry CD-ROM (included with your other main text,
Chemistry and Chemical Reactivity, Kotz and Treichel, 5
th
 edition). These CD-
ROM references are not essential to learn this course, but we highly
recommend their use to gain a better understanding of the principles involved.
Some topics have been expanded from these prescribed materials, and others
given lesser emphasis or even omitted. This reflects our philosophy regarding
the relative importance of the various aspects of organic chemistry to be
covered in the unit.
The ordering adopted is based on that which has been found to be successful in
teaching the internal unit.  This permits the introduction of new topics and
concepts to be used as a revision of earlier parts of the unit.  Nonetheless, the
endpoint arrived at is essentially the same as that of the prescribed text.
Study Guide: CHEM110  - Organic Chemistry 2
I I I In n n n    t t t th h h he e e e    b b b be e e eg g g gi i i in n n nn n n ni i i in n n ng g g g. . . .. . . .. . . .. . . .. . . .. . . .. . . .. . . .
Friedrich Wöhler expressed a view of organic chemistry with which some
newcomers to the discipline might have some sympathy. In a letter to Jons
Jacob Berzelius in 1835, he wrote:
"Organic Chemistry just now is enough to drive one mad.  It gives me the
impression of a primeval tropical forest, full of the most remarkable things; a
monstrous and boundless thicket, with no way of escape, into which one may
well dread to enter".
Berzelius in 1808 had been involved in the isolation and study of chemicals
derived from living sources; the view at the time was that such "organic"
substances as they were known could not be synthesised in the laboratory from
"inorganic" materials, because it was believed that a "vital force" which was
possessed only by living organisms was necessary to produce organic
compounds.
This "Vital Force Theory" was challenged by Wöhler in 1828 when he heated
the inorganic compound ammonium cyanate (NH
4
OCN) and obtained urea
which was recognised as being "organic" because it could be isolated from
urine.
A few years later August Kekulé assigned the modern definition of organic
chemistry - organic compounds are those containing carbon.
Likewise Leopold Gmelin in 1848 defined organic chemistry as “the chemistry
of the compounds of carbon which occur naturally”.  This definition is too
restrictive, however - although many organic compounds are of natural origin,
the great majority owe their existence to the endeavours of academic and
industrial chemists.  Some may only have been synthesised in milligram
quantities (or less!) whereas others are manufactured annually on the scale of
millions of tonnes.
And let us not forget that all living matter is constructed of a multitude of
(mainly very complex) organic chemicals and that life processes are the
reactions of these chemicals.
In 1848 Wöhler was to write:
“The Philosopher of Chemistry will draw the conclusion that the production of
all organic matters in our laboratories, in as much as they do not belong any
more to the organism, must be regarded not only as probable but as certain.  It
is true we do not know the methods by which this final result will be reached,
because the rudiments are unknown from which they are to be developed, but
we shall know them in time”.
A magnificent statement for 1848!
Wöhler indicated various target natural products, among them morphine:  80
years were to elapse before the structure of morphine was elucidated and a
further 20 years before its synthesis was achieved.
Study Guide: CHEM110  - Organic Chemistry 3
How can we succeed?
What is the best way to study organic chemistry?  In many ways it can be
likened to learning a new language, and like the use of language
communication is both oral and written.
The written component of the organic chemistry language is the structural
formula, but while one can frequently get by with an ungrammatical sentence, a
badly drawn (ungrammatical?) structure is useless.
The structure of a compound determines its reactivity, so the need for accuracy
in drawing structures is paramount.  This accuracy can only be achieved by
practice with pen on paper:  the task is rather like learning multiplication tables
in primary school-eventually the correct structure will (we hope) be drawn
automatically. Even professional chemists started this way and they
communicate extensively by drawing structures.  At least the written language
is universal!
Production of correct pictures needs precision in drawing which leads to
precision in thinking.
W W W Wh h h hy y y y    i i i is s s s    c c c ca a a ar r r rb b b bo o o on n n n    s s s so o o o    s s s sp p p pe e e ec c c ci i i ia a a al l l l? ? ? ?
Read
Brown, Chapter 1.1 – 1.4
It is a characteristic of carbon that it forms strong covalent bonds with other
carbon atoms, and with certain other elements, particularly hydrogen (carbon
and hydrogen differ in electronegativity by only 0.4 on the Pauling scale).  The
carbon - carbon bond energy for a single bond is around 350 kJmol
-1
.  This
is among the strongest of covalent bonds between like atoms of any element.
Carbon can also form multiple bonds, that is, double and triple bonds readily.
The first point allows carbon to form an enormous variety of chains and rings,
and this is the reason for the diversity of organic compounds.  There are more
than 10 million compounds listed in Chemical Abstracts, and most of these are
organic.  Fortunately we can classify them into a few dozen families.  This
classification is based on structural entities which have a chemical reactivity
that is roughly predictable - so-called functional groups.  We won’t cover
them all, but by the end of the course the principles will be well apparent to
you.
Two of the simplest examples, both containing carbon chains are:
H
C
H
C
H
C H
HH H
H
C
C
C
C
C
C
HH
H
H
HH
H H
H H
H
H
and
propane
cyclohexane
General
Chemistry
CD-ROM
Screen 11.3