Molecular Formula and the Degree of Unsaturation

molecular formula = CnH2n+2 – 2 hydrogens for every π bond or ring

degree of unsaturation = the total numbers of π bonds and rings

Compounds with Molecular Formula = C8H14

CnH2n+2 = C8H18

Therefore, C8H14 has two degrees of unsaturation.

compounds with six hydrogens and two degrees of unsaturation

Saturated and Unsaturated Hydrocarbons

Saturated hydrocarbons have no double bonds.

Unsaturated hydrocarbons have one or more double bonds.

Nomenclature of Alkenes

Replace “ane” of alkane with “ene.”

The functional group gets the lowest possible number.

Stereoisomers are Named Using a cis or trans Prefix

Nomenclature of Dienes

two double bonds = diene

Number in the direction so that the functional group gets the lowest number.

Nomenclature of Alkenes

Substituents are stated in alphabetical order.

Nomenclature of Alkenes

Nomenclature of Alkenes

Nomenclature of Cyclic Alkenes

A number is not needed to denote the position of the functional group;

it is always between C1 and C2.

Nomenclature of Alkenes

Nomenclature of Alkenes

Vinylic and Allylic Carbons

vinylic carbon: the sp2 carbon of an alkene

allylic carbon: a carbon adjacent to a vinylic carbon