Questions tagged [alcohols]
For questions about saturated and unsaturated alcohols, their physical properties, their reactions, etc. For questions about phenol, use the [phenols] tag instead.
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Reaction of alcohols with PCl5 and PCl3
The reaction of alcohols $\ce{ ROH }$ with $\ce{ PCl5 }$ and $\ce{ PCl3 }$ yields an alkyl halide $\ce{RCl}.$ With $\ce{ PCl5 }$, the reaction is quite simple leading to the formation of $\ce{ RCl }$ ...
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Why can't alcohols form hydrogen-bonded dimers like carboxylic acids?
Carboxylic acids such as acetic acid are capable of forming dimers:
I'm wondering why alcohols like ethanol don't generally form dimers. In the diagram below, the oxygen atom on the left ethanol ...
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Migratory aptitude in pinacol-pinacolone rearrangement
I am confused about the migratory aptitude of various groups, as there are many different orders for the same given in different places, especially about -Ph and -H. I would like to know if someone ...
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Reactions of alcohol with sulfuric acid
I knew two chemical reactions of alcohol with sulfuric acid
$\ce{CH3CH2OH + H2SO4 -> CH2CH2}$
Here product is having a double bond (ethene) and this reaction happens at 443 K temperature.
$\ce{...
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Mechanism for oxidation of primary alcohols to carboxylic acids
My teacher told me that the following is the mechanism for oxidation of primary alcohols to carboxylic acids:
I've searched in books and online and didn't find a similar mechanism. For example, in ...
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How do I predict the solubility of a compound in a mixture of water and an organic co-solvent?
I'm trying to predict the solubility of long alcohols (e.g. 1-octanol, 1-decanol or 1-dodecanol) in a mixture of water and an organic co-solvent such as DMSO, acetonitrile or ethyl acetate.
For ...
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Is methanol really more acidic than water?
The question Why is methanol more acidic than water? deals with the reasoning of why methanol is more acidic than water. However, as mentioned in the comments of that question, the acidity constant of ...
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Is Pinacol rearrangement the source for the ring expansion?
I have no idea what's happening as in the product (the answer is (a)) there is a new ring being formed on the left benzene. But as I studied after $\ce{H2O}$ leaves, a carbocation is then formed on ...
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Reaction of ethylene glycol with PI₃ (P + I₂)
We know that $\ce{2P + 3I2 -> 2PI3}$
Ethylene glycol reacts with $\ce{PCl3}$ to give ethylene dichloride, but why does it gives ethylene when it reacts with $\ce{P + I2}$?
I don't really know ...
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Halogenation of alcohols in the presence of ZnCl2
I know that $\ce{OH-}$ is usually a bad leaving group, but why does the following reaction occur via SN1 in presence of anhydrous $\ce{ZnCl2}$?
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Differences between phenols and alcohols
I know phenols are more acidic as compared to alcohols, but are they considered different from alcohols?
Sure, you can study something as a subset, but are phenols considered a subset of alcohols, or ...
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Can we synthesize alcohols by the photolysis of hydrogen peroxide?
As I was going through my revision of organic chemistry, I came across free radical substitution of alkanes with halogens. In a similar process where we use hydrogen peroxide, instead of chlorine, so ...
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Reaction of secondary alcohol with ammoniacal silver nitrate (Tollens' reagent)
What are the products of the reaction of 2-butanol with silver nitrate?
For the moment, I am a bit stumped as I only have $\ce{AgNO3}$ as an oxidizing agent to form a carboxylic acid from an aldehyde....
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Why do hydroxyl groups only produce a singlet in proton NMR?
Take, for example, methanol ($\ce{CH3OH}$). The hydroxyl proton ($\ce{-O$\color{red}{\ce{H}}$}$) is three bonds away from three more protons ($\ce{-C$\color{blue}{\ce{H}}$_3}$), which aren't ...
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Why do tosylation and mesylation of alcohols follow different mechanisms?
Why do the tosylation and mesylation of an alcohol proceed via different mechanisms?
More specifically,
In tosylation, the lone pair of the alcohol attacks the sulfur in TsCl, but why does it not ...
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Why is the melting point of tert-butyl alcohol 140 °C higher than that of sec-butyl alcohol?
This is one of the most drastic differences in a physical property I've ever seen for two such similar molecules, and in a simplistic sense anyway the difference lies in the opposite direction from ...
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Have "molecular clusters" for azeotropes been identified?
A different question about azeotropes got me thinking about this point again. Azeotropes have a very specific composition so it seems that the azeotrope ought to have some sort of physical structure. ...
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False positive in lucas test for primary alcohol due to formation of tertiary carbocation by rearrangement?
From Wikipedia:
The Lucas test in alcohols is a test to differentiate between primary, secondary, and tertiary alcohols. It is based on the differences in reactivity of the three classes of alcohols ...
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How does the inductive effect, explain the reactivity of tertiary alcohols with halogen acids?
The reactions of primary and secondary alcohols with halogen acids ($\ce{HX}$, where $\ce{X}$=halogen) require the presence of a catalyst, $\ce{ZnCl_2}$. With tertiary alcohols, the reaction is ...
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Why don't alcohols undergo nucleophilic substitution with ammonia?
Alcohols can undergo nucleophilic substitution with $\ce{PCl5, POCl3, HCl}$. Halogenoalkanes can undergo nucleophilic substitution with $\ce{NH3}$. The $\ce{C-O}$ (in alcohol) and $\ce{C-Cl}$ (in ...
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Benzene from cyclopropane-1,2,3-triyltrimethanol in acidic medium
What is the mechanism of the conversion of cyclopropane-1,2,3-triyltrimethanol to benzene in in acidic medium?
After performing E1 thrice I was expecting 1,2,3-trimethylidenecyclopropane to form ...
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Formation of toluene from (cyclobutane-1,2,3-triyl)trimethanol using conc. sulphuric acid
In my book this reaction is given without any mechanism:
I thought that simple dehydration reaction is going to take place with rearrangement of the carbocation but I have no idea as to how toluene ...
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Saturation of multiple solutes
Can a liquid which is saturated with a single solute, dissolve a different solute, or is saturation a universal thing? I ask because I’ve seen that different solutes have different points (amounts) at ...
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Phenol or ethanol as a nucleophile for ether formation?
If we react phenol with $\ce{C2H5I}$ in $\ce{C2H5O- Na+}$ (excess), $\ce{C2H5OH}$ (anhydrous) solutions .
In this reaction why is diethyl ether not formed and the actual product is phenyl ethyl ...
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What is the OH in alcohol?
What is the $\ce{OH}$ functional group in alcohol (ethanol)? My teacher told me it isn't the same as the $\ce{OH-}$ ion or hydroxide.
But it does donate one electron to the respective carbon chain and ...
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2
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Why and how does ring expansion occur in the dehydration of (cyclobut-3-ene-1,2-diyl)dimethanol?
Can someone explain how does this ring expansion occur with the mechanism? I do understand that the hydride shift occurred because of carbocation stability but why did the ring expand? Can you please ...
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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 ...
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Oxidation of alcohols by Ceric Ammonium Nitrate
I have realized that reaction with ceric ammonium nitrate essentially results in coordination of alcohol with $\ce{Ce(IV)}$ and my teacher referred that we should be able to proceed it to form ketone ...
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What is more important, to have the parent chain be the cycle or the chain that has an hydroxyl group
I know how to name alcohols, I just don't know what I should chose as the parent chain. Should I chose the cycle or the chain with the hydroxyl group. Here is an example:
My current algorithm tells ...
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Why does the reaction of the primary alcohol cyclopentylmethanol with hydrogen bromide follow SN1 mechanism?
Example 2: Identify all the products formed in the following reaction and indicate the major product.
Solution: Three products will be formed in the given reaction as shown below:
In this reaction ...
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Rearrangement of 8a-ethyl-1,3,4,8a-tetrahydronaphthalen-4a(2H)-ol [closed]
really sorry for that previous post. I was actually half-asleep when I posted that q, hence the q was unclear. I am again reposting that question
The answer is given as A. Can anyone please explain ...
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How do you create primary amines from alcohols?
By a primary amine I mean a compound where the hydroxyl group of the corresponding alcohol is replaced with an amine group.
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Ring contraction in pinacol rearrangement of cyclohexane-1,2-diol
I came across this question in three different textbooks.
The question was: What is the major product obtained on dehydration (treatment with concentrated $\ce{H2SO4}$) of cyclohexane-1,2-diol.
I ...
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Which electronic effects are responsible for the reduction of nucleophilicity of a hydroxy group orthogonal to an ester?
I am facing a similar synthetic problem as Boekman Jr. et al noted in their synthesis of Tetronolide.[1] I will quote their’s rather than disclosing my actual synthetic problem, but note that the key ...
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Why is thionyl chloride preferred for preparing alkyl chlorides from alcohols?
Why is thionyl chloride ($\ce{SOCl2}$) preferred for preparing alkyl chlorides from alcohols, as opposed to say $\ce{PCl5}$ or $\ce{PCl3}$ ?
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How could alcohol be made into a powder?
In the news recently is 'Palcohol', powdered alcohol, that you add to water or existing liquids to make it alcohol. Presumably this would dissolve and break apart into alcohol and {some other compound}...
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How does SO2Cl2 react with alcohols?
Is the mechanism similar to the reaction of $\ce{SOCl2}$ with alcohols?
If not, then how is it different? We have been taught about the latter at school but my friend quizzed me about $\ce{SO2Cl2}$.
...
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Mechanism for bromoetherification of olefinic alcohol
Propose a mechanism for the following reaction showing the relevant stereochemistry of intermediates and the final product.
I am confused as to what is going on here. I guess there's some sort of ...
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Producing ketones from secondary alcohols using hydrogen peroxide
Usually, to produce ketones from secondary alcohols (e.g. propanone from 2-propanol), people use a solution of potassium or sodium dichromate with a small amount of sulfuric acid. Can other oxidizers ...
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Do amines or alcohols have stronger intermolecular hydrogen bonds?
Which has stronger hydrogen bonding, $\ce{CH3OH}$ or $\ce{CH3NH2}$
I think it comes down to which has more dominance; number of hydrogens, number of lone pairs, or electronegativity.
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Why is the Lucas test not recommended to differentiate higher alcohols?
I read about the Lucas test for alcohols in which a cloudy precipitate is produced with a tertiary or secondary alcohol. However, on a side note it was mentioned that this test is useful only for ...
user78585
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Why are 1,3-diols protected with aldehydes but 1,2-diols are protected with ketones?
1,3 diols are usually reacted with benzaldehyde when protection of the OH groups is desirable, but acetone is used when the relation between the hydroxyl groups is 1,2. Why is it so?
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Protonation of tetrahydrofurfuryl alcohol
I think the ethereal oxygen in THFA gets protonated. Due to greater +I effect, the electron density on it is higher, hence it is more likely to behave as a Lewis base. Consequently, the product formed ...
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Electrolysis of Beer
Electrolysis of water, means that the water is separated into hydrogen and oxygen. As beer also includes water, I initially thought electrolysis of beer would cause the water to separate, and the ...
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How to find trace methanol content in fermented fruit/distillate?
Suppose we have some fermented (optionally also distilled) fruit/fruit juice. The sample therefore contains water, sugars, ethanol etc. Which analysis method is the simplest to find out whether the ...
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RO (alkoxide) as a leaving group
Why is RO (alkoxide) a better leaving group than OH, despite RO being more unstable due to the electron donating effect of the alkyl group on RO?
I read that the suitability of leaving groups is ...
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Purification of Ethanol
In Vogel's organic book, they have mentioned that in the Lund and Bjerrum method of purification of ethanol, magnesium is added, which forms ethanolate. But they said to activate the magnesium first ...
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Rate of O exchange with H2O
We have to find the order of rate of exchange of O with H2O of the following compounds
$\ce{CCl3CHO}$
$\ce{CH3CHO}$
$\ce{CH3COCH3}$
$\ce{CF3CHO}$
According to me, higher rates of exchange would be ...
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Solubility of methanol and ethanol in water
Which substance is the most soluble in water?
$\ce{CH3OH}$
$\ce{CH4}$
$\ce{C2H6}$
$\ce{C2H5OH}$
I wasn't able to decide between 1 and 4, as both have hydroxides, but the answer is 1. ...
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Can oxidation of ethanol by copper(II) oxide yield copper(I) oxide as one of the products?
We know that ethanol is oxidised by copper(II) oxide to an aldehyde. Copper is reduced from $\ce{Cu^2+}$ to $\ce{Cu}$. Can this reaction, with some specific condition, yield $\ce{Cu2O}$ instead? That ...
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