Chapter 12 Flashcards
Synthesis and Retrosynthesis
What is a phenol?
a benzene + alcohol
What is a alkoxide?
deprotonated form of an alcohol
What is needed to form an alkoxide?
strong base
ex. NaH
How is acidity in alcohols determined?
Resonance - more resonance = increased acidity
Induction: presence of electron withdrawing groups increases acidity
Solvation: more poorly solvated (bulky)=acidic
What is the best way to make a 1 prime alcohol?
SN2
What is the best way to make 3 prime alcohols?
SN1
What are the three ways to prepare an alcohol from an alkene and which reagents do they use?
- Acid-catalyzed hydration: Dilute H2SO4
- Oxymercuration: 1)Hg(OAc)2, H2O
2)NaBH4 - Hydroboration: 1) BH3THF
2)H2O2, NaOH
What is the order of oxidation?
alcohol to aldehyde/carbonyl to carboxylic acid
What are the common reducing agents?
- NaBH4
- LiAlH4
What is a diol compound?
compound with two hydroxyl groups
What are the Grignard reagents used to prepare and alcohol?
1)CH3MgBr, Et2O
2)H3O+
(CH3 can be any type of carbon chain)
What protects alcohol groups from modification in a Grignard rxn?
TMS (trimethylsilyl group)
TMSCl
———->
Et3N
What are the options for the substitution of primary alcohols?
1)Simple substitution: primary alcohol +HBr
2)Catalyzed substitution:
primary alcohol + HCl ZnCl2
———>
What are the options for the substitution of primary or secondary alcohols?
1) 2alcohol + TsCl/Pyr +Cl -
- inverts stereochemistry
2)1 alcohol +PBr3—-> OH substituted with Br
3)2* alcohol (SOCl2)/—–> Cl swaps with OH and is inverted
What are the methods for forming an alkene from the elimination of alcohols?
- Acid-Catalyzed Elimination:
3* alcohol (H2SO4)/—>/(delta Heat)
via E1, - Base-catalyzed elimination
TsCl/Pyr + EtONa (strong base) - E2 mechanism
What does the oxidation of 1* alcohol lead to?
Carboxylic acid
What does the oxidation of 2* alcohol lead to?
Ketone
What does the oxidation of 3* alcohol lead to?
Does not happen bc it would lead to 5 bonds to carbon
What are the four types of oxidation reactions?
- Chromium Oxidation
- controlled oxidation
- swern oxidation
- Dess-Martin Oxidation