# Tag Info

## Hot answers tagged carbonyl-compounds

19

Does folic acid contain a benzyl or a phenyl group? This is the question asked in the title. At the first glance to the structure, one would say folic acid consists of phenyl function but not benzyl function because the question did not define what is the phenyl group. In reality, phenyl group $(\ce{Ph})$ is $\ce{C6H5}$. As Poutnik pointed out in the ...

12

It is known that $\ce{Mg}$ will reduce ketones. The articles (Ref.1 and 2) in the References section confirm this fact. If you want to form the Grignard reagent of a molecule that also happens to contain a carbonyl group, then the usual practice is to protect it first. A cyclic ketal/acetal, which are stable under basic conditions, is often the first choice ...

9

Unlike other reducing metal hydrides (e.g., $\ce{NaBH4}$ and $\ce{LiAlH4}$), diisobutylaluminum hydride (DIBAL-H) is a liquid at room temperature and dissolve in many hydrocarbons such as toluene and hexanes, which also have very low freezing points. For example, hydrocarbons toluene and hexanes both have freezing points around $\pu{-95 ^\circ C}$. Thus, ...

8

I see what went wrong. Such questions are often confused with aldol or cannizarro as they have a carbonyl group and a base is given. Actually this is a completely different name reaction called Favorskii rearrangement. The key to identify it is that its applicable to α-halo ketones. In Favorskii rearrangement, the base takes α-hydrogen from that side of ...

8

Because the target structure contains the motif of a cyclohexane-1,2-diol, I suggest an approach including a Diels-Alder reaction (DA in the illustration below) of 1,3-butadiene and the commercially available diethyl acetal of propargyl aldehyde: The hydrolysis of the acetal then sets the stage to install the methyl group with the cuprate and 1,4-...

8

Following are the Statement from “On Terephthalic Acid and its derivatives” By Warren De la Rue and Hugo Muller February 7, 1861: On heating, terephthalic acid sublimes without previously fusing(melting). The sublimate, which is indistinctly crystalline, has the same composition and properties as the original acid, and therefore, unlike other bibasic acids, ...

7

The problem in ortho-aminobenzoic acid is that the acidic hydrogen of carboxylic group is H-bonded with the lone pair of nitrogen in amino group. As a result it is more difficult to extract it compared to that in para-aminobenzoic acid since the H-bond must also be broken during acid-base reaction. Para-aminobenzoic acid does not have a H-bond due to the ...

7

It will depend on strict control of the equivalents of reductant, your work-up conditions and your control of temperature during the workup. The intial product of the reduction is the aluminium alkoxide. If you use a proton source such as $\ce{HCl (aq)}$ or $\ce{NH4Cl (aq)}$ to quench the alkoxide and keep the reaction mixture cold then you will get the 4-...

7

Similar to to last step of aldol condensation to give $\alpha, \beta$-unsaturated ketone, the last elimination step at sought reaction is also supposed to undergo elimination of water molecule through $\mathrm{E1_{cb}}$ mechanism. To refresh your memory, the definition of the $\mathrm{E1_{cb}}$ mechanism is as follows: An elimination reaction mechanism ...

6

@user1055 answered the question pretty much. I am just going to add a complementary answer which has the abstract to the paper which @user1055 mentioned. The abstract of the paper mentions the various products of the decomposition reaction: The thermal decomposition behavior of terephthalic acid (TA) was investigated by thermogravimetry/differential thermal ...

6

The reduction of alkyl halides to the corrosponding alkane by $\ce{LiAlH4}$ is well known reaction: $$\ce{R-X + LiAlH4 -> R-H + AlH3 + LiX}$$ This reaction has been studied in some details (For example, Ref.1). Accordingly, the major product from the reaction of 4-chloropentanal and $\ce{LiAlH4}$ would be pentanol after simultaneous carbonyl and halide ...

5

According to The Hazardous Substances Databank entry for acrolein here An extremely violent polymerization reaction of acrolein results from contact with alkaline materials such as sodium hydroxide, potassium hydroxide, ammonia and amines. Mixing sodium hydroxide and acrolein in a closed container caused the temperature and pressure to increase. The next ...

5

D and L configuration of sugars: Draw the given sugar (aldose) in the Fischer projection with the most oxidized carbon at the top (i.e. aldehyde carbon). If it is a ketose, make the closest terminal carbon to the keto group at the top. Now: if the $\ce{OH}$ on the bottom chiral center points to the right hand side, the sugar is referred to as D-sugar. if ...

5

First, there is a little mistake in your reasoning. You said that the carbanion is more stable on the unsubstituted side but actually, forming an enolate on the more substituted side will give a more stable substituted alkene. Remember, the negative charge is not concentrated on carbon. It is concentrated on the oxygen atom as the system is conjugated. That ...

5

Since primary amino acids like glycine, alanine can't be decarboxylated under oxidative conditions, what would be the best catalyst for this reaction? Decarboxylation of $\alpha$-amino acids is known enzymatic procedure in biological systems. Non-enzymatic decarboxylation of $\alpha$-amino acids is also a long-known reaction, which leads to amines with a ...

5

α,β-Unsaturated carbonyl compounds, for the most stable intermediate with respect to $\ce{H-}$ ion prefer 1,4-addition. However, $\ce{LiAlH4}$ prefers 1,2-addition over 1,4-addition. This can be explained due to the following reasons. It is more reactive so it prefers a kinetically favorable pathway (1,2-addition is often kinetically favored while 1,4-...

5

There are two characteristic reactions of $\alpha$-keto acids with sulphuric acid, but none of them produce acetic acid and carbondioxide as the products as indicated in the reaction given in the OP's textbook. Instead, pyruvic acid (the simple $\alpha$-keto acid shown in the textbook reaction) is easily decarboxylated with warm dilute sulphuric acid to give ...

5

The backbonding, as I know, is proportional to the number of electrons in the d-orbital That's indeed part of it — and that explains why the early d-block metals, Sc and Ti, don't form (neutral) carbonyls at all. However, the backbonding also depends on how willing the metal is to share those d-electrons. $Z_\mathrm{eff}$ increases going across the 3d block,...

4

Might as well make an answer of the comments. Aldehydes are not only able to be oxidized to acids, they are quite reactive towards this oxidation. Exposure to air would be enough to trigger enough oxidation and acid formation to get litmus to react, especially if the litmus is moist. Aldehydes are not alone in this respect; for example iron(ii) salts can ...

4

The answer to this question is actually pretty interesting, I think. @user55119 's comment that the principal chain is the cyclohexane ring is correct -- but it seems like you understand that that's what the teacher is saying, and you're asking, "why?" The best short answer, too, is imho in your comments: @MaxW 's "naming organic compounds ...

4

Yes, it is important to convert your silver ion to diamminesilver(I) complex. If you do not add ammonia to silver nitrate, the silver ion is reduced so quickly that colloidal silver metal would appear and the solution would become a black, cloudy liquid and you won't get the silver mirror when it reacts with aldehyde. It is also important that you maintain ...

4

Your line of thought possibly is influenced by the Walden inversion which is characteristic for the nucleophilic substitution mechanism of $\mathrm{S_N2}$ where steric hindrance affects the rate when this umbrella-like structure flips upon entry of the nuclophile and departure of the nucleofuge around a formally $\mathrm{sp^3}$ hybridized center: (credit) ...

4

Conversion 1 Convert ethene to ethanol. Ethene is mixed with steam and passed over a catalyst consisting of solid silicon dioxide coated with phosphoric(V) acid. The temperature used is 300 °C and the pressure is about 60 to 70 atmospheres (chemguide — The mechanism for the acid catalysed hydration of ethene). \ce{CH2=CH2 + H2O <=>[H3PO4] CH3CH2OH}$... 4 I appreciate Waylander's answer. However, although the answer gives you the basic mechanisms for Reimer–Tiemann and Kolbe-Schmidt reactions, it does not address some question and OP's misconceptions such as: The$\ce{CO2}$liberated will react with the phenol. Thus, I'd like to address these by using the same starting materials used in the question. ... 3 This is the mechanism of the Reimer-Tiemann reaction (source Wikipedia here) The polyhaloform reacts with strong base to create a carbene, a highly reactive species which reacts with the phenoxide anion through the alpha carbon to give an anionic intermediate with the -ve charge on the halogenated carbon. It is this species that picks up the deuterium. In ... 3 For the first case, we need to compare benzamide and ethanamide, One of the ways I can think of is comparing aniline and methylamine. But we need to get there first, so we first react both our substrates with$\ce{Br2/NaOH}$(Hoffman Bromamide degradation). As taken from Chem Libretexts/Hoffman Degradation: Hofmann rearrangement, also known as Hofmann ... 3 In 1928, Malaprade demonstrated that periodic acid reacted with ethylene glycol to produce iodic acid and formaldehyde (Ref.1). Hence, the oxidation of adjacent diols with periodic acid or its salt in aqueous solution is now generally known as the Malaprade reaction, the mechanism of which is depicted below: The reaction proceeds faster under acidic ... 3 Based on a quite old reference 1 (which I'm using because it's available free by open access), peptide bond formation at 25 C is unfavorable only because of a large enthalpy change, on the order of 1.5 kcal/mol (6.3 kJ/mol). The entropy change is actually favorable, with$T\Delta S$being about 1 kcal/mol (4kJ/mol), so the net free energy change is ~ + 500 ... 3 The molecule in black consists of a cyclic ketal and a hemiacetal. The hemiacetal is known to be in equilibrium with its aldehyde form, which is the the molecule in blue, in aqueous solutions even without$\ce{NaOH}\$. Recall the reaction of glucose (a cyclic hemiacetal) with dilute sodium hydroxide, which is known as Lobry de Bruyn-van Ekentein rearrangement ...

3

You are indeed correct, a study by Karthikeyan et. al.[1] suggests that the Dipole moment of terephthalic acid is indeed around ~2.6D (in air), the same as your latter source. From the paper, The calculated dipole moment of the title compound is 2.57 Debye in gas and 3.14 in solvent The same paper later mentions, The calculated value of dipole moment is ...

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