Advices For Studying Organic Chemistry

hydrocarbon ring system and use the prefix oxa- to indicate that an oxygen atom

replaces a CH 2 group.

2) Oxirane: a cyclic three-membered ether (epoxide).

3) Oxetane: a cyclic four-membered ether.

4) Common names: given in parentheses.

O

O

Oxacyclopropane Oxacyclobutane
or oxirane (ethylene oxide) or oxetane

O

O

O

Oxacyclopentane 1,4-Dioxacyclohexane
(tertahydrofuran) (1,4-dioxane)

4. Tetrahydrofuran (THF) and 1,4-dioxane are useful solvents.

11.2 PHYSICAL PROPERTIES OF ALCOHOLS AND ETHERS

1. Ethers have boiling points that are comparable with those of hydrocarbons of the
   same molecular weight.

1. The b.p. of diethyl ether (MW = 74) is 34.6 °C; that of pentane (MW = 74) is 36
   °C.

2. Alcohols have much higher b.p. than comparable ethers or hydrocarbons.
   
   
   1. The b.p. of butyl alcohol (MW = 74) is 117.7 °C.
   
   
   2. The molecules of alcohols can associate with each other through hydrogen
      bonding, whereas those of ethers and hydrocarbons cannot.
   
   
   
   


3. Ethers are able to form hydrogen bonds with compounds such as water.
   
   
   1. Ethers have solubilities in water that are similar to those of alcohols of the same
      molecular weight and that are very different from those of hydrocarbons.