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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Is 99% Isopropyl Alcohol sold in stores really 99%?

My understanding is that an azeotropic mixture of isopropanol and water is 91%. This makes sense as to why there are so many brands of rubbing alcohol sold at 91%. There are also some sold as 99%, ...
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1answer
140 views

dehydration of an alcohol (3-methyl-1-phenylbutan-2-ol)

I was thinking of dehydrating this alcohol: 3-methyl-1-phenylbutan-2-ol Its structure is: My concern is which of the following would it form: The problem is that the first one comes from a stable ...
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Darzens reaction on allylic position

Question Attempt I thought the products would be from simple darzens reaction. So I replaced the $\ce{OH}$ by $\ce{Cl}$. But the answer of mine seems way wrong. Do give some tips on what might be ...
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Why is chlorosulfite a good leaving group?

I came across the following website article[1]: I understand the mechanism and also get the fact that this is nothing but an experimental result but why does the $\ce{ClSOO-}$ group departs ...
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What is role of copper powder, calcium chloride and cuprous chloride in the SN1 reaction of hydrochloric acid with propargylic alcohol?

For the synthesis of a 2H-cromene from a phenol I need to prepare 3-chloro-2-methyl-but-1-yne from the corresponding alcohol 2-methylbut-3-yn-2-ol. This reaction could be seen as a simple $S_\text N1$ ...
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What is the solubility order of isomeric alcohols in water?

The order for the solubility of isomeric alcohols in a book was given as: Primary alcohol >Secondary alcohol >Tertiary alcohol After this I found a question: (1) Which is more soluble in water? ...
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When does reaction of alcohol with alumina give ethers and when an alkene?

This problem given in my book confused me a little bit: when an excess of ethyl alcohol vapour is passed over heated alumina ($250^\circ$C), the main product is? I read that this reaction gives an ...
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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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Why does a methyl shift occur during the pinacol-pinacolone rearrangement?

Why does a methyl shift occur during the pinacol-pinacolone rearrangement? I was told that methyl shift is done to stabilise the carbocation but here we are shifting the ...
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What is the product of the reaction between alcohol and acetyl chloride in presence of pyridine?

What happens when butan-2-ol reacts(under heat) with $\ce{CH3COCl}$ in the presence of pyridine? Does it form $\ce{CH3COOCH(CH3)CH2CH3}$? I got the ester mentioned but the solution says it gives an ...
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Does a reaction proceed through SN1 if rearrangement results in a stable carbocation?

While going through my book I came across the following problem: I thought it was safe to assume that the secondary alcohol would give SN1(although secondary alcohols give significant amount of both ...
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Preparation of Alcohols from Grignard Reagent

We were given this question in the class: Answer given: I got 2-Methyl Butanol. Why doesn't the methyl attack the 2nd carbon atom from the oxygen atom and form 2-Methyl Butanol instead of attacking ...
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Un-denaturing industrial alcohol

I have a question regarding the denaturation of industrial ethanol with methanol to discourage its consumption. The boiling point of methanol is 64.7 °C, while the boiling point of ethanol is 78.37 °...
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1answer
608 views

How is the nucleophilicity of alkoxy groups related to acidity and +/- inductive effects due to substituents?

I found a nucleophilicity order as $\ce{HO-} > \ce{CH3-O-} > \ce{(CH3)2CH-O-} > \ce{(CH3)3C-O-}$ The reason was given that bulky groups reduce nucleophilicity. But why? The order of the $+...
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Do azeotropic mixtures evaporate proportionally?

Do azeotropes evaporate, without boiling, in proportionate amounts, or does this property describe their behaviour only at boiling point? Concretely, if 91% isopropyl alcohol/water (by volume, i.e. an ...
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479 views

Why is ethanol distilled off before adding water in the first step of a malonic synthesis?

I am doing a malonic synthesis shown below, and I wonder why I should distill ethanol off before adding water in the first step of the reaction (First I add absolute ethanol and solid sodium).
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What is/are the product when 2,2-dimethylhex-5-en-3-ol reacts with Lucas reagent?

What would be the product(s) if 2,2-dimethylhex-5-en-3-ol reacts with Lucas reagent? Would a Methyl shift happen? I've heard that in Groove's process, only primary and secondary alkyl chlorides are ...
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Major product of the dehydration of alcohols

Well I was doing some questions and I have a bit of confusion on dehydration reaction. For instance, consider following reaction: How do I decide which adjacent hydrogen gets attracted by $\ce{HSO4-}$...
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Predicting product ratio by rearrangement in Dehydration Reactions

I came across this question recently, which would have a clear major product. The OP has given satisfactory explanation for the product ratio, but wasn't sure about the major product. When I was ...
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1answer
570 views

Acid Catalyzed Hydration of an Alkene Synthesis Problem

Devise syntheses of the following three compounds, starting in each case with any alkene that contains four carbons or fewer. You do not have to write mechanisms, although at this point it may be very ...
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Making a bridge on a cyclic molecule

So, my question is how would I make a bridge as seen on the following molecule (right side)? As for the molecule on the left, I am supposed to make it using that molecule as a base. The only ...
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Doubt in dehydrations of alcohol where ring expansion may be involved [duplicate]

I came across this question in my book. Now I have always thought that alcohol dehydration takes place through E2 mechanism when primary carbocation is involved. So I made the following product for ...
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Why am I getting higher conversion values of isopropanol dehydration over a zeolite catalyst than n-propanol dehydration?

The two process are run separetly but under the same condition, same activation of the catalyst, same reaction temperature, same flow. The initial conversion of n-propanol is ~50% and isopropanol ~70%....
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why doesn't alcohol react with sodium hydroxide but react with potassium hydroxide? [closed]

I have read that ROH+ NaOH doesn't form alkoxide ions because water is a stronger acid than all alcohols except methanol. However while reading xanthate test I found that alcohol reacts with KOH to ...
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Is it safe to mix methylated spirits with isopropyl alcohol?

I have about 200ml of methylated spirits and 500ml of 100% isopropyl alcohol that I want to mix together in a plastic drink bottle. I will use it for fuel in an alcohol burning stove while camping. ...
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186 views

Rearrangement in dehydration of alcohol

I came across the following problem in my book: Now my confusion is how will cyclohexene be obtained? I read that primary alcohols dehydrate by E2 mechanism because of formation of a primary ...
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Is it possible to distinguish between cyclohexanol and cyclohex-2-en-1-ol with simple chemical test?

Primary, secondary and tertiary alcohols can easily be distinguished by using reagent tests such as: The triiodomethane test for $\ce{R-CH(CH3)OH}$ alcohols. Lucas' reagent to distinguish between ...
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1answer
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Reduction of epoxide

Does $\ce{LiAlH4}$ and $\ce{NaBH4}$ reduce an isolated epoxide? I have two books where both are saying differently. One says it can and other says cannot. On searching the web there was no definite ...
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Confusion regarding mechanism of dehydration of alcohols [closed]

1)Today I came across a problem which asks to find the order of dehydration of 2-hydroxycyclohexanone(1), 3-hydroxycyclohexanone(2),4-hydroxycyclohexanone(3). The answer is 2>3>1 But I thought ...
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Intramolecular Cannizzaro reaction product

I came across the following question : My reasoning was as follows : It can't be option (c) because there is no chance of losing a carbon during Cannizzaro's reaction It can't be option (b) because ...
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Determining the mechanism followed when alcohols undergo a reaction with sodium bromide and sulphuric acid

$$\ce{R-OH + NaBr + H2SO4 -> R-Br + NaHSO4 + H2O}$$ Due to sulphuric acid, the $\ce{-OH}$ group will get protonated and convert into $\ce{-H2O+}$ which is a great leaving group in comparison to the ...
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Why does the C−H bond dissociation energy vary in a homologous series of primary alcohols?

Specifically, for the primary carbon atom in the alcohol. Here is bond dissociation energy (BDE) data from chapter three of Luo's Comprehensive handbook of chemical bond energies [1] (boldface refers ...
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Methanol-water mix freezing points - clarify contradictory online data > 60% w/w?

Extending an exploration of windshield washer-fluid choices to freezing points of methanol-water mixes, all web-sources located agreed to within a couple of degrees from 0-60% w/w, yet above this ...
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1answer
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Extent of dehydration by concentrated sulphuric acid

I know that conc $\ce{H2SO4}$ is a dehydrating agent. And the most easiest mechanism for example would be this: But I want to know how to find the extent of dehydration of it. I came across this ...
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Is my bottle of “RooR”-brand glass cleaning liquid pure isopropyl alcohol or something else?

I have this exact bottle: https://www.grasscity.eu/media/catalog/product/cache/2b55fa971a29a7844993ad77b24950ac/i/m/img_3633_1_1.jpg I originally purchased it to clean my vaporizer (I've since stopped ...
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1answer
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On the molybdenum(III) oxide-catalysed oxidation of alkanes to carbonyls

The following reaction is specified in my notes; $$\ce{CH4 ->[Mo2O3, \Delta]HCHO}$$ The intermediate steps involve the dehydration of an alcohol to yield the final product. Wouldn't this only work ...
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Periodic acid oxidation of carbonyls?

The following reaction seem to be valid; $\ce{CH2OH-CHOH-CH2OH ->[HIO4]CH2O + HCOOH + CH2O + 2H2O}$ Apparently, there are similar reactions by 2,3-dihydroxypropanal, and also by the straight chain ...
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Why there is a color fading ( to colorless) when Cerium Ammonium Nitrate (CAN) is mixed with ethanol or butanol? [duplicate]

I have mixed CAN in butanol and also ethanol (separately), the solution became dark red immediately but after a couple of minutes the color totally faded and turned into a transparent solution, I am ...
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1answer
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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 ...
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Show the mechanism of the Pinacol-Pinacolone Rearrangement reaction [duplicate]

In the reactant, due to $\ce{H+}$ ion, a positive charge will be created by removing water in place of the rightmost $-\ce{OH}$. But then how will it give such a product. I cant see any way to make ...
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1answer
160 views

IUPAC name of cyclopentanol derivative

Is the name of the following compound 3-(ethenyl)-5-(prop-1-enyl)-2-(prop-1-ynyl)-4-(prop-2-enyl)cyclopent-2-en-ol? The problem I am facing is that how do I arrange 5-(prop-1-enyl), 2-(prop-1-enyl) ...
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1answer
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Why does Ethylene Glycol have higher boiling point than Propylene Glycol?

Looking at the two alcohols, both have hydrogen bonding and are singly bonded throughout the molecule. However, propylene glycol has a larger electron cloud which to my knowledge would increase its ...
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Is 6-ethenyl-4-(prop-2'-enyl) octa-6-en-3-ol a valid name?

I recently study organic chemistry and I read a book by Sana Jamshaid. I came across this compound and I cannot understand why it named 6-ethenyl-4-(prop-2'-enyl) octa-6-en-3-ol: I understand that ...
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1answer
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Lucas test in the presence of EWG like -CN

Does the given compound give Lucas test? My teacher says due to the presence of a strong electron withdrawing group the carbocation formed is unstable. But I say if it undergoes $\mathrm{S_N2}$ ...
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Is the negative excess volume of ethanol/water the cause of my math error?

I have a binary mixture, say ethanol at $90\%wt$ ethanol, $10\%wt$ water. According to Perry's Chemical Engineers' Handbook 9th Ed., that mixture has a density of $0.81797g/cc$ (at $20^{\circ}C$). ...
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Possibility of removing two water molecules from glycerol

Not a chemist, but from a chemical formula perspective, how hard would it be to create acetone by acidifying glycerol? $$\ce{C3H8O3 + 2 H+ <=> C3H6O + 2 H2O}$$ Has anyone ever heard of this ...
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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 ...
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3answers
126 views

How to verify that ethanol is infinitely soluble in water?

My textbook [Chemistry Live, Declan Kennedy] states that ''Ethanol is said to be infinitely soluble in water''. It then says ''verify this for yourself by mixing some ethanol with water in a test tube'...
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Why hydrogen bonds are stronger than Van der Waals forces?

Why the hydrogen bonds are more intense than Van der Waals forces in the case where the molecules with the Van der Waals forces have a stronger dipolar moment than the molecules with the hydrogen bond?...
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Will OTs ever act as a nucleophile and substitute with an alcohol?

If you reacted TsOH with a secondary or tertiary alcohol, will you ever see a racemic mixture of OTs substituted products after the water group leaves? Is OTs just too weak of a nucleophile to ever ...

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