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What is the product from R-OH through the below techniques?
1) dehydration
2) oxidation
3) substitution
4)reduction
5) esterification
6) tosylation
7) form alkoxide; R'X
- 2) alkene
- 2) ketones, aldehydes, acids
- 3) halides
- 4) alkanes
- 5) esters
- 6) tosylate esters
- 7) ethers
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Explain the oxidation of alkanes.
alkane oxidized to alkene oxidized to alkyne
alkane oxidized to alcohol oxidized to ketone/ aldehyde oxidized to carboxylic acid
alkane oxidized to chloroethane oxidized to dichloroethane oxidized to trichloroethane
alkane oxidized to amine (NH2)--> NH--> CN
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oxidation of secondary alcohols with Cr(VI)
What is the mechanism?
leads to a ketone
secondary alcohol + chromic acid---> chromate ester--> ketone
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Oxidation of primary alcohols with chromic acid
1) to aldehydes
2) to carboxylic acids
- 1) DMP, Swern Oxidation, PCC
- 2) chromic acid and NaOCl
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__is a complex of chromium trioxide, pyridine, and HCl.
Oxidizes primary alcohols to __.Oxidizes secondary alcohols to __
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What do tertiary alcohols get oxidized to?
nothing; they cannot be oxidized
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Tertiary Alcohols:
Caron does not have __, so oxidation is difficult and involves the breakage of a __.
Chromic acid test is for __because tertiary alcohols do not react. __ color of Cr(VII) turns __- Cr(III); tertiary alcohol is not oxidized, therefore __.
- hydrogen
- C—C bond
- primary and secondary alcohols
- Orange
- green
- no color change
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•__ (household bleach) can oxidize alcohols without heavy metals or generating hazardous waste.
This is a much better option for acid-sensitive compounds
Sodium hypochlorite
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•__, with __and __, oxidizes 2° alcohols to __and 1° alcohols to __(same as __). This reaction is called the __.
- Dimethylsulfoxide (DMSO)
- oxalyl chloride
- hindered base
- ketones
- aldehydes
- PCC
- Swern Oxidation
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Oxidation summary of primary:
R-OH + Chromic acid and NaOCl --> carboxylic acid
R-OH + PCC --> aldehyde
R-OH + DMP, DMSO (Swern) --> aldehyde
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Reduction Summary
Reduction of aldehyde or ketone to alcohol--> NaBH4 and LiAlH4
Reduction of carboxylic acid or ester--> LiAlH4
Reduction by Raney Nickel
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Conversion of alcohol into a leaving group
- form tosylate (p-TsCl, pyridine)
- use strong acid (H3O+)
- convert to alkyl halide (HX, SOCl2, PBr3)
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How to Form p-Toluenesolfonate esters
alcohol + TSOH
(R-O-H + HO-Ts <---> R-O-Ts + H2O)
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Substitution and Elimination Reactions using Tosylates:
Attack by a nucleophile (back side attack) displaces the leaving group and adds the nucleophile in substitution
Attack by a base deprotonates the molecule, moving the electrons to become a double bond, causing the OTs to leave
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R-OTs + LiAlH4-->
R-OTs + R'-O- -->
R-H and -OTs
R-O-R' + -OTs
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Base to use p-TsCl with pyridine
R-OH + Cl-Ts---> ROTs + HCl
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Reduction of alcohols
dehydrate with concentrated H2So4 then add H2
CH3-CH2-OH ---(H2SO4)--> CH2=CH2--- (H2, Pt)--> CH3-CH3
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Alcohols to Alkyl Halides:
- Tertiary
- Secondary
(CH3)3-C-OH + HX (HCl, HBr)---> (CH3)3-CX: rapid Sn1 (forms a tertiary carbocation)
R2-CH-OH + HX ---> R2-CH-X
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Reaction of alcohols with acids:
-The __ is protonated by an __ to convert it into a good leaving group (H2O)
- Once the alcohol is protonated, a __ or __ can take place.
- hydroxyl group
- acid
- leaving group
- substitution
- elimination
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Reaction of alcohols with acids:
R-O-H + H+ ---> _____ ----> _____
R-O-H2 + X- ----> R_X
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Reactions of alcohols with Hr
1) ___ of alcohol is protonated
2) ___ is good LG
3) __ and __ react with Br- via __.
4) __ react via __.
-OH
-OH2+
- tertiary and secondary alcohols
- Sn1
primary alcohols Sn2
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What is the Lucas Test? Why is it used?
It is the formation of two separate layers when a reaction occurs with an alkyl bromide
the Lucas reagent is utilized in a reaction to form the alkyl halide (HCl + ZnCl2)
Secondary react with the Sn1 mechanism, as do tertiary
Primary react with the Sn2 (slow)
- The Lucas Test:
- tertiary react less than a minute
- secondary react 1-5 minutes
- primary take forever to react
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Sn2 reaction with the Lucas Reagent:
1) __ react with the Lucas reagent by the Sn2 mechanism
2) Reaction is very slow. The reaction can take from __ to __.
primary alcohols
- several minutes
- several days
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Other qualitative tests:
- Alcohols
- Alkenes
With chromic acid, primary and secondary go from orange to green/blue
alkenes: reddish-brown--> colorless
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Primary and secondary alcohols: best to use what to make alkyl halides?
All are __.
CH3-OH ---> SOCl2---> CH3-Cl
CH3-OH ---> PBr3--> CH3-Br
CH3-OH ---> CH3-I
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Thionyl Chloride mechanism in pyridine is __. What is the mechanism?
Sn2 inversion
CH3-OH --> CH3-OH-SO(Cl2)----> CH3-OH-SOCl + -H+ ---> CH3-O-SOCl + Cl- ----> CH3-Cl
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Dehydration of alcohols:
1) Alcohol dehydration generally takes place through the __.
2) __ are possible.
3) The rate of the reaction follows the same rate as the ease of formation of __: __
4) __ rearrange, so this is not a good reaction for coverting __ into __.
E1 mechanism
rearrangements
carocations
3>2>1
primary alcohols
primary alcohols
alkenes
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__ is faster than the loss of H+.
methide shift
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Esterification:
(5 of them)
Fischer: Alcohol + carboxylic acid
tosylate esters
sulfate esters
nitrate esters
phoshate esters
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Fischer Esterification:
Reaction of an __ and __ produces an ester.
___ is a catalyst.
The reaction is an equilibrium between __ and __, and for this reason the __ is seldom used to prepare esters.
alcohol and a carboxylic acid
sulfuric acid
starting materials and products
Fischer esterification
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Fischer Esterification Method:
R-O-H + H-O-C=OR' <--> R-O-C=OR' + H-O-H
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Nitrate esters:
The best-known nitrate ester is __, whose systematic name is __.
__ results from the reaction of glycerol (1,2,3-propanetriol) with three molecules of nitric acid.
- nitroglycerine
- glyceryl trinitrate
Glyceryl nitrate
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__ temporarily convert reactive functional groups into unreactive groups in a simple, high-yielding reaction.
protecting groups
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