Advertisements
Advertisements
Question
Which of the following reagents can be used to oxidise primary alcohols to aldehydes?
(i) \[\ce{CrO3}\] in anhydrous medium.
(ii) \[\ce{KMnO4}\] in acidic medium.
(iii) Pyridinium chlorochromate.
(iv) Heat in the presence of Cu at 573 K.
Advertisements
Solution
(i) \[\ce{CrO3}\] in anhydrous medium.
(iii) Pyridinium chlorochromate.
(iv) Heat in the presence of Cu at 573 K.
Explanation:
Strong oxidising agents such as acidified potassium permanganate are used for getting carboxylic acids from alcohols directly. \[\ce{CrO3}\] in anhydrous medium is used as the oxidising agent for the isolation of aldehydes.
\[\ce{RCH2OH ->[CrO3] RCHO}\]
A better reagent for the oxidation of primary alcohols to aldehydes in good yield is pyridinium chlorochromate (PCC), a complex for chromium trioxide with pyridine and HCl.
APPEARS IN
RELATED QUESTIONS
Name the following compound according to IUPAC system.
\[\begin{array}{cc}
\ce{CH3 - C = C - CH2OH}\\
\phantom{}|\phantom{....}|\phantom{....}\\
\phantom{}\ce{CH3}\phantom{.}\ce{Br}\phantom{...}
\end{array}\]
Give IUPAC name of the following ether:
O2N – C6H4 – OCH3(p)
Ethylidene dichloride when boiled with aqueous solution of NaOH yields _______.
(A) formaldehyde
(B) acetaldehyde
(C) acetone
(D) ethyl methyl ketone
Which of the following compounds is NOT prepared by the action of alcoholic NI3 on alkyl halide?
(a) CH3NH2
(b) CH3- CH2- NH2
(c) CH3 - CH2 - CH2 - NH2
(d) (CH3)3 C- NH2
Give reasons Fluoride ion has higher hydration enthalpy than chloride ion.
How do you convert the Ethanal to Propanone
In the dehydration of alcohols to alkenes by heating with concentrated sulphuric acid, the initiation step is:
(1) formation of carbonation
(2) formation of an ester
(3) protonation of the alcohol molecule
(4) elimination of water
Write structural formulae for 3-Methoxyhexane
Write structural formulae for Cyclohex-2-en-1-ol.
In a carbinol system of nomenclature tert.butyl alcohol is named as _______________
Butane-2-ol is ____________.
Which of the following compounds is oxidised to prepare methyl ethyl ketone?
HBr reacts fastest with ____________.
When ethyl alcohol reacts with acetic acid, the products formed are:
Write steps to carry out the conversion of phenol to aspirin.
Assertion: Addition reaction of water to but-1-ene in acidic medium yields butan-1-ol.
Reason: Addition of water in acidic medium proceeds through the formation of primary carbocation.
Give the structures of Thiosulphuric acid and Peroxy monosulphuric acid.
Write structural formulae for:
p-Nitrophenol
Write the IUPAC name of the following compound:
\[\begin{array}{cc}
\phantom{...............}\ce{CH3}\\
\phantom{.............}|\\
\ce{CH3 - CH - CH - C - CH3}\\
|\phantom{......}|\phantom{......}|\\
\phantom{...}\ce{CH3}\phantom{..}\ce{OH}\phantom{...}\ce{CH3}
\end{array}\]
