Organic Chemistry - Cycloalkanes

Front 1

most organic compounds contain ___ of carbon atoms

Back 1

rings

Front 2

___ contain four rings joined together

Back 2

steroids

Front 3

cycloalkanes ar ___ ___ ___

Back 3

saturated cyclic hydrocarbons

Front 4

alicyclic

Back 4

aliphitic cyclic

Front 5

general formual of cycoalkanes

Back 5

CnH2n

Front 6

cycloalkanes can be represented by what shapes?

Back 6

polygons (triangles, squares, pentagons, hexagons)

Front 7

naming rules for cycloalkanes

Back 7

1. find the parent (dictated by the number of carbon atoms in the ring, and the longest chain of carbon, if the ring has more or equal number of carbon than the chain, then it is a alkyl-subsituted cycoalkane, otherwie it's a cycloalkyl-substituted alkane)

2. For an alkyl- or halo-substituted cycloalkane, choose a point of attachment as carbon 1 and number them so that the second substituent is as close as possible)

Front 8

what is an alkyl-substituted cycloalkane?

Back 8

a cycloalkane with an alkyl substituent

Front 9

what is a cycloalkyl-substituted alkane?

Back 9

an alkane with a cycloalkyl (ring) substituent

Front 10

in naming cycloalkanes, when two or more substituent groups could receive the same numbers, order them ____

Back 10

alphabetically

Front 11

the chemistry of cycloalkanes is a lot like alkanes in that they are ____ and fairly ___

Back 11

non polar, inert

Front 12

cycloalkanes are less ___ than open-chain alkanes

Back 12

flexible

Front 13

why are cycloalkanes less flexible than open chain alkanes?

Back 13

the bonds cannot rotate

Front 14

larger cycloalkanes have increasing ___ freedom

Back 14

rotational

Front 15

largets cycloalkanes are so ___ that sometimes they are indistinguishable from the open chain ones

Back 15

floppy

Front 16

molecules with the same atoms in the same order but different in 3D spatial orientation are called ___

Back 16

stereoisomers

Front 17

same side, different side isomers are called ___

Back 17

cis-trans isomers

Front 18

cis-

Back 18

same side

Front 19

trans-

Back 19

opposite side

Front 20

angle strain

Back 20

when bond angles are forced to deviate from the ideal angle 109 (happens when rings form)

Front 21

why is baeyers theory on angle strain wrong?

Back 21

because he assumed the ring molecules to be flat, but they are flexible, so they try to create tetrahedral bond angles

Front 22

angle strain occurs only on ___ rings that have little flexibility

Back 22

small

Front 23

for most ring sizes ___ and ___ strain are the most important factors

Back 23

torsional and steric

Front 24

difference between angle torsional and steric strain

Back 24

-angle strain is due to expansion or compression of bond angles

- torsional strain is due to the eclipsing of bonds on neighboring atoms

- steric strain is due to repulsive interactions when atoms approach each other too closely

Front 25

How many eclipsing hydrogen atoms are in cyclopropane?

Back 25

6

Front 26

___ is the most strained of all rings, primarily because of all of the ___ strain, but also because of the ___ strain

Back 26

cyclopropane, angle, torsional strain

Front 27

How can cyclopropane bond with hybrid orbitals when it's angles are 60 degrees? and what does that do to the chemistry of cyclopropane?

Back 27

it has bent bonds, causing the orbitals to overlap at an angle and making the bonds weaker and more reactive

Front 28

cyclobutane has less __ strain but more __ strain than cyclopropane, causing their total strain to be __

Back 28

angle, torsional (more hydrogen), equal

Front 29

cyclopentane (when in a plane) has nearly zero ___ strain, but a large amount of ___ strain

Back 29

angle, torsional

Front 30

cyclopentane will twist and pucker to strike a balance between more ___ and less __ strain

Back 30

angle strain, torsional

Front 31

____ ____ are the most common cycloalkanes

Back 31

substituted cyclohexanes

Front 32

cyclohexane adopts a strain free, 3D shape called a _____

Back 32

chair conformation

Front 33

cyclohexane in chair conformation has zero __ and zero ___ strain. Why?

Back 33

angle, because the bond angles are near 109, and torsional, because all of the hydrogen atoms are staggered with the ones closest

Front 34

why does twist-boat conformation cyclohexane have torsional and steric strain?

Back 34

torsional because some of the hydrogen atoms are now eclipsed, and the two carbon atoms at the bottom of the boat are closer and cause steric strain

Front 35

which conformation of cyclohexane is more stable?

Back 35

chair

Front 36

what are the two kinds of positions for substituents on the cyclohexane ring?

Back 36

six axial and six equatorial

Front 37

each carbon atom in chair cyclohexane contains one __ and one __ hydrgoen

Back 37

axial, equatorial

Front 38

In cyclohexane rings, a substituent is always more stable in the __ position, than in the ___ position.

Back 38

equatorial, axial

Front 39

The energy difference between axial and equatorial conformations is due to ___ strain between 1,3 diaxial interactions.

Back 39

steric (they are too close)

Front 40

The amount of steric strain due to axial conformations increases with ___

Back 40

longer chain substituents

Front 41

two or more cyclic rings are fused together

Back 41

polycyclic

Front 42

the two carbons joined to fuse a polycyclic compound

Back 42

bridgehead carbons