Parent Names for Alkanes + Names of Alkyl Groups/Sub

1 C

meth (methane)

2 C

eth (ethane)

3 C

prop (propane)

4 C

but (butane)

5 C

pent (pentane)

6 C

hex (hexane)

7 C

hept (heptane)

8 C

oct (octane)

9 C

non (nonane)

10 C

dec (decane)

11 C

undec (undecane)

12 C

dodec (dodecane)

1 C in Sub

methyl

2 C in Sub

ethyl

3 C in Sub

propyl

4 C in Sub

butyl

5 C in Sub

pentyl

6 C in Sub

hexyl

7 C in Sub

heptyl

8 C in Sub

octyl

9 C in Sub

nonyl

10 C in Sub

decyl

Branched alkyl group with 3 C

isopropyl (1-methylethyl)

Branches alkyl groups with 4 C

tert-butyl (1, 1-dimethylethyl)

If the parent chain is cyclic…

add the prefix “cyclo”

Prefixes are ignored when…

alphabetizing the substituents

Isomers

different structures, same molecular formula

Constitutional Isomers

different connectivity of atoms

Conformations

single bonds rotate, resulting in multiple 3D shapes

Newman projections

ideal for comparing the relative stability of possible conformations resulting from single bond rotation (focus on specific bond)

Angle between atoms on adjacent carbons

Dihedral angle

Staggered conformations are…

more stable, lower in E

Eclipsed conformations are…

less stable, higher in E

Torsional strain

Reason for difference in energy between the staggered and eclipsed conformations