Org 10 - Ethers & Phenols Flashcards
What is the general structure of an Ether ?
N.B. ‘R’ groups may be aliphatic or aromatic
What is the process for naming Ethers ?
Name the two groups either side of the ‘O’ and add ‘Ether’ to the end. The names appear in alphabetical order.
Describe the boiling points of Ethers ?
Comparable to other hydrocarbons, relatively low compared to alcohols.
Ethers are more polar but less capable of forming Hydrogen bonds.
Describe the stability of Ethers in Water ?
Only slightly soluble, but can form inter-molecular hydrogen bonds.
What will happen to an Ether in the presence of a high concetration of a strong acid ? E.g. HI or HBr
The ether linkage will be cleaved forming an alcohol and a Alkyl halide.
Name two important reactions of Ethers ?
- Williamson Ether synthesis (Sn1)
- Acidic Cleavage
What is a 3-membered cyclic ether also known as ?
Epoxide
What is Phenol ?
Describe acidity in Phenols ?
More acidic than their corresponding alcohols due to the electron withdrawing ad resonance stabilisation effects of the aromatic ring.
What is the effect of substituent groups on Phenol ?
- Effect acidity by inductive effects (E.g. Alcohols) and resonance effects
- Electron stabilising (Withdrawing/meta directing) goups at ortho and para positions increase the acidity of the phenol
What groups are likely to make phenol more acidic ?
Electron stabilizing (E.g. withdrawing or meta-directing) groups at ortho and para positions, E.g:
Nitro group NO2
CN
CO2H
Halogens
What substituent groups are likely to make Phenol less acidic ?
Destabilizing groups e.g. Alkyl groups
Describe boiling point and solubility trends in phenols ?
- Fairly high boiling point due to ability to form hydrogen bonds
- Limited solubility in water due to hydrophobic nature of the aromatic ring
Describe the main reaction of Phenols ?
- Electrophilic aromatic substitution
- The hydroxyl group is a powerful activating group, and an ortho-para director, eg. Phenols can brominate 3x in Bromine Water.
