Chapter 14

Question 1

C-O-C bond angle is _______, very close to tetrahedral bond angle

Answer 1

110

Question 2

Ethers are not able to form hydrogen bonds, so they have a much _______ boiling point than alcohols of similar MW

Answer 2

lower

Question 3

Ethers have a slight dipole due to electronegative oxygen atom so they have _______ boiling points than similar MW hydrocarbons

Answer 3

higher

Question 4

Ethers are hydrogen bond _______, whereas alcohols are both hydrogen bond _______ and _______

Answer 4

acceptor
donors and acceptors

Question 5

Ethers are widely used as solvents. What are the 3 reasons?

Answer 5

1) they can dissolve nonpolar and polar substances
2) they are unreactive to strong bases
3) they have low bp so easy to seperate

Question 6

Ethers solvate __1___ and not __2___ allowing for __2__ to be free for reaction

Answer 6

1) cations
2) anions

Question 7

Explain how ether works in Grignard reagents:

Answer 7

stabilizes the Mg reagent and allows the partial negative to be free to react

Question 8

Explain how ether works in electrophiles (BH3):

Answer 8

the ether’s nonbonding electrons stabilize the borane

Question 9

Explain how crown ether complexes work for metal cations

Answer 9

1) 12-cr-4 solvates Li+
2) 15-cr-5 solvates Na+
3) 18-cr-6 solvates K+

Question 10

What are the rules for the common name for ethers:
1) name the 2 alkyl groups attached to the oxygen in _______ order
2) add the word _______ at the end
3) if both groups are same, name it __ alkyl ether

Answer 10

1) alphabetical
2) ether
3) di

Question 11

What are the rules for IUPAC naming for ethers:
1) the more _______ alkyl group is the alkane name
2) the small group becomes an “_______” group

Answer 11

1) complex
2) alkoxy
- methoxy, ethoxy

Question 12

cyclic ethers (_______): oxygen is part of a ring

Answer 12

heterocyclic

Question 13

What are the rules for common name for epoxides:
1) name the starting alkene and add _______

Answer 13

1) oxide
the starting alkene is the double bond before mCPBA

Question 14

What are the rules for IUPAC naming for epoxides:
1) the oxygen can be treated as a substituent (___,___-______)
2) the ring can be named as a root (_______) oxygen is 1, and carbons 2 and 3 are determined by # for substituents

Answer 14

1) #,#-epoxy
2) oxirane

Question 15

What is the best method for ether synthesis?

Answer 15

Williamson ether synthesis

Question 16

Williamson ether synthesis method involves an _____ attack of the alkoxide on a 1° or methyl halide or OTs

Answer 16

SN2

Question 17

What are the 3 leaving groups that are good for Williamson ether synthesis?

Answer 17

1) methyl halide
2) 1° halide
3) OTs

Question 18

When preparing unsymmetrical ethers by williamson ether synthesis, use ____ hindered alkoxide with _______ hindered alkyl halide

Answer 18

SN2
less

Question 19

When would you use alkoxymercuration-demurcuration over Williamson Ether synthesis?

Answer 19

Use alkoxymerc-demerc if you have a 2° or 3° alkyl halide
- E2 then merc-dmerc