Organic Structure #1: Alkanes & Cycloalkanes
Hydrocarbon: compound that contains only carbon atoms and hydrogen
What Are Alkanes?
Alkanes: saturated hydrocarbon whose carbon atoms are arranged in an
o Contain only carbon-carbon single bonds, maximum number of
hydrogens bonded to it
o Four bonds of each carbon atom are still arranged in a tetrahedral
manner and all bond angles are approximately 109.5°
Line-Angle Formula: abbreviated way to draw structural formulas in which
each vertex and each line ending represents a C atom and a line
represents a bond
General formula – C n 2n+2(end in –ane)
What Is Constitutional Isomerism in Alkanes?
Constitutional Isomers: compounds with the same molecular formula but a
different order of attachment of their atoms
o These compounds differ in the kind of bonds they have or in their
o Different compounds, different physical & chemical properties
o All compounds that have same molecular formula but different
Ability of C atoms to form strong, stable bonds with other C atoms results
in staggering number of constitutional isomers
How Do We Name Alkanes?
Alkyl Group: group derived by removing a hydrogen from an alkane (R-)
C atom is classified as 1°, 2°, 3°, or 4° depending of the number of C
atoms bonded to it
H atom is classified as 1°, 2°, 3° depending on the type of C to which it is
What Are Cycloalkanes?
Hydrocarbon that contains C atoms joined to form a ring is called a cyclic
Cycloalkane: saturated hydrocarbon that contains C atoms joined to form
Contain two fewer H atoms than alkane with the same number of C atoms
Five-membered rings and six-membered rings are especially abundant in
biological world What Is The IUPAC System of Nomenclature?
The name we give to any compound with a chain of C atoms consists of
the three parts: prefix, infix (modifying element inserted into a word), and a
What Are The Conformations of Alkanes And Cycloalkanes?
Alkanes with two or more C can be twisted into a number of different 3D
arrangements of their atoms by rotating about