contain more than one ringcontain more than one ring

bicyclicbicyclic

tricyclictricyclic

tetracyclictetracyclic

etcetc

3.143.14

Polycyclic Ring SystemsPolycyclic Ring Systems

spirocyclicspirocyclic

fused ringfused ring

bridged ringbridged ring

Types of Ring SystemsTypes of Ring Systems

one atom common to two ringsone atom common to two rings

SpirocyclicSpirocyclic

adjacent atoms common to two ringsadjacent atoms common to two rings

two rings share a common sidetwo rings share a common side

Fused RingFused Ring

nonadjacent atoms common to two ringsnonadjacent atoms common to two rings

Bridged RingBridged Ring

equals minimum number of bond equals minimum number of bond disconnectionsdisconnectionsrequired to give a noncyclic speciesrequired to give a noncyclic species

Number of RingsNumber of Rings

requires one bond disconnectionrequires one bond disconnection

MonocyclicMonocyclic

requires two bond disconnectionsrequires two bond disconnections

BicyclicBicyclic

requires two bond disconnectionsrequires two bond disconnections

Bridged BicyclicBridged Bicyclic

carbon skeleton is tetracycliccarbon skeleton is tetracyclic

SteroidsSteroids

3.153.15

Heterocyclic CompoundsHeterocyclic Compounds

a cyclic compound that contains an atom other a cyclic compound that contains an atom other

than carbon in the ringthan carbon in the ring

(such atoms are called heteroatoms)(such atoms are called heteroatoms)

typical heteroatoms are N, O, and Stypical heteroatoms are N, O, and S

Heterocyclic CompoundHeterocyclic Compound

Ethylene Ethylene oxideoxide

TetrahydrofuranTetrahydrofuran

TetrahydropyranTetrahydropyran

Oxygen-containing HeterocyclesOxygen-containing Heterocycles

O

O

O

O

PyrrolidinePyrrolidine PiperidinePiperidine

Nitrogen-containing HeterocyclesNitrogen-containing Heterocycles

N H

N

H

Lipoic acidLipoic acid

LenthionineLenthionine

CHCH22CHCH22CHCH22CHCH22COHCOH

OO

SS

SS

SS

S

Sulfur-containing HeterocyclesSulfur-containing Heterocycles