- CYCLOALKANES, CnH2n
- NOMENCLATURE
- I. NO SUBSTITUENTS
- NOMENCLATURE
- ADD PREFIX
- --- CYCLO (one word)
- II. SUBSTITUENTS
- 1. MONOSUBSTITUTED
- a. ALKYL GROUPS
- Determine if the ring or the alkyl group has more carbon atoms
- b. HALOGEN GROUPS
- BROMOCYCLOPROPANE
- Determine if the ring or the alkyl group has more carbon atoms
- MULTIPLE SUBSTITUENTS
- a. NAME AS CYCLOALKANE
- b. NUMBER RING ATOMS TO GIVE THE LOWEST SUM
- c. DIFFERENT ALKYL GROUPS LOWER IN THE ALPHABET GETS THE LOWER NUMBER
- EXAMPLE, answer
- EXAMPLE, answer
- b. NUMBER RING ATOMS TO GIVE THE LOWEST SUM
- STEREOISOMERS
- cis-trans isomers
- DIFFERENT MP, BP, ETC.
- HAVE TO BE DIFFERENT COMPOUNDS
- SAME CONNECTION BETWEEN ATOMS
- NOT CONSTITUTIONAL ISOMERS
- ISOMERS WHICH HAVE THE SAME ORDER OF CONNECTION BUT HAVE A DIFFERENT THREE-DIMENSIONAL ORIENTATION ARE CALLED STEREOISOMERS
- cis-trans isomers
- HOW DO YOU DRAW THREE DIMENSIONAL MOLECULE IN TWO DIMENSIONS?
-
DASH-WEDGE NOTATION REVIEW
- RING STRAIN
- CYCLOPROPANE
- ----HARD TO FORM
- ----VERY REACTIVE
- ----60 DEGREE BOND ANGLES (NOT 109.5)
- -------SHOULD HAVE ANGLE STRAIN!
- HOW ABOUT OTHER RINGS
- HOW DO WE CHECK RELATIVE ENERGIES?
- ENERGY VIDEO (available only in the Chemistry Computer Lab)
- HISTORICAL NOTE
- MEASURE HEAT OF COMBUSTION: Kcal/mol CH2
- CYCLOPROPANE = 166.6
- CYCLOBUTANE = 164.0
- CYCLOPENTANE = 158.7
- CYCLOHEXANE = 157.4
- CYCLOHEPTANE = 158.3
- CYCLOOCTANE = 158.6
- ANGLE STRAIN IS NOT THE WHOLE ANSWER!
- RING STRAIN
- CYCLOPROPANE, INTERACTIVE VIEW
- CYCLOBUTANE
- CYCLOPENTANE
- CYCLOHEXANE
- CYCLOHEXANE IS AS FREE OF ANGLE STRAIN AND TORSIONAL STRAIN AS A RING CAN BE! INTERACTIVE VIEW
- SIX MEMBERED RINGS ARE THE MOST STABLE!
- SIX MEMBERED RINGS ARE THE MOST COMMON IN NATURE!
- WE WILL LOOK AT SIX MEMBERED RINGS EXTENSIVELY!
- YOU NEED TO BE ABLE TO DRAW "CHAIR" CYCLOHEXANE!
- NOTE THAT CYCLOHEXANE HAS TWO DIFFERENT KIND OF HYDROGEN ATOMS!
- YOU NEED TO BE ABLE TO DRAW AXIAL AND EQUATORIAL BONDS!
- RING-FLIP QUICKTIME MOVIE
- AXIAL ---> EQUATORIAL
- EQUATORIAL ---> AXIAL
- MONOSUBSTITUTED CYCLOHEXANES (METHYLCYCLOHEXANE)
- WHICH CONFORMATION OF METHYLCYCLOHEXANE IS MORE STABLE?
- AXIAL OR EQUATORIAL METHYL?
- INTERACTIVE VIEW OF METHYL-EQUATORIAL
INTERACTIVE VIEW OF METHYL-AXIAL
- GAUCHE BUTANE = 0.9 kcal/mol
- AXIAL METHANE HAS TWO "GAUCHE" BUTANE INTERACTIONS
- 1.8 kcal/mol DIFFERENCE
- 6% AXIAL, 94% EQUATORIAL
- SIMILIAR FOR OTHER SUBSTITUENTS QUICKTIME MOVIE OF T-BUTYLCYCLOHEXANE RING-FLIP
- cis-trans isomers