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2 votes
0 answers
38 views

Which 1,2-methylene shift is more favourable in ring expansions where ring has substituents

In the above reaction, first the -OH group is protonated after which it leaves creating a carbocation intermediate as shown Now, ring expansion is a more favourable rearrangement, however there is a ...
Pravimish's user avatar
  • 169
6 votes
1 answer
469 views

When does reaction of alcohol with alumina give an ether and when an alkene?

What is the main product when an excess of ethyl alcohol vapour is passed over heated alumina at 250 °C? I read that this reaction gives an ether (here, diethyl ether) at relatively lower temperature ...
Prajwal Tiwari's user avatar
2 votes
2 answers
501 views

On the relative ease of E2 dehydration

Concerning alcohol dehydration, I get that it's E1 in secondary and tertiary alcohols, that it's E2 in primary alcohols, and also why E1 reaction is easier for tertiary alcohols as compared to ...
harry's user avatar
  • 1,134
2 votes
0 answers
69 views

Confusion regarding dehydration of 1° alcohols

My lecturer told me that 2° and 3° alcohols prefer to dehydrate through E-1 mechanism. On the other hand, 1° alcohols tend to prefer the E-2 mechanism, which does not involve the formation of a ...
C_Lycoris's user avatar
  • 608
6 votes
1 answer
2k views

Major product in dehydration of alcohol

Consider the dehydration of the following molecule with conc. $\ce{H2SO4}$ at $443 \text K$: The possible products are: The first one is the Zaitsev product and the second one Hofmann product. ...
newbie105's user avatar
  • 397
3 votes
2 answers
542 views

Rate of dehydration of alcohols having keto group

The following question was asked in IITJEE-Screening 2000, Which of the following will be most readily dehydrated in acidic conditions? I thought that the answer would simply be (c), as its ...
Rahul Verma's user avatar
  • 3,071
1 vote
1 answer
448 views

Conversion of methylcyclopentanol to cyclopentanone

How to convert methylcyclopentanol to cyclopentanone? I tried eliminating the alcohol group as $\ce{H2O},$ but that gives Saytzeff product. If only I can get the Hofmann product (methylene ...
Yashwini's user avatar
-1 votes
1 answer
18 views

Where will the positive charge shift in the E1 mechanism of dehydration of an alcohol? [closed]

My Attempt: according to me the double bond should be in position no. 2 but the correct answer has a double bond in position no.1. Why is it so? Thanks in advance.
SLADE's user avatar
  • 13
4 votes
1 answer
1k views

When does a pinacol undergo dehydration or rearrangement?

What happens when the above pinacol is treated with - (a) conc. sulphuric acid (b) dil. sulphuric acid I'm confused between pinacol rearrangement and dehydration (E1 or E2?), as both possibilities ...
stoic-santiago's user avatar