Questions tagged [organic-chemistry]

Use this tag for questions relating to organic molecules and their properties (structure of organic molecules, spectroscopic properties, reaction mechanisms, stereochemistry etc). DO NOT use this tag as the only tag in your question, as this tag by itself cannot appropriately classify your question. Always use this tag in addition to other more specific tags.

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Reaction of soap with water

I've seen it many times... Why does soap become foam-like when it reacts with water (moisture) or when we touch it with wet hands.. What compound actually causes this physical change? And why does ...
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Why do lipids in a cell hydrolyze into glycerol and fatty acids?

Most Lipids in a cell have ester bonds (made up of glycerol and fatty acids). I have learned in my chemistry class that we can hydrolyze an ester by simply adding water to it. $$\ce{CH3COOCH2CH3 + ...
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What is the chemical structure of the cocoate ion vs. the olivate ion?

I am wondering how the cocoate ion (in natural soaps, in the form of sodium or potassium cocoate and from the saponification of coconut oil) differs structurally from the olivate ion (from the ...
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1answer
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What is the molecular structure of the coating on cast iron cookware known as seasoning?

When a piece of cast iron is repeatedly covered in fat and exposed to heat it develops a hard, black, non-stick coating referred to as "seasoning". What exactly is this coating made of molecularly? ...
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1answer
282 views

What does the ZZE tag in an Chemical Table file refer to?

I have a number of Chemical Table files which include a "M ZZE" tag in the properties block. For example, in Galactobuxin, I have: M ZZE 1 31 23 In ...
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Differences between KOH and phosphorus pentoxide as drying agents?

The most common drying agent I encountered when using a vacuum dessicator was phosphorus pentoxide in the form of Sicapent. But I've recently encountered people using KOH as a cheaper alternative (in ...
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699 views

Cyanogenic glycosides and HCN

I'm researching cyanide for a biology project and noted that one of the largest sources of carbohydrates in the tropics is the cassava root -- which I previously researched as a food that contains a ...
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Which cyclohexane conformation is more stable?

I got this question wrong on a test and I don't know why: Question: Which conformation is more stable? Answer: the chair on the left is more stable. I thought that the ring conformation ...
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1answer
239 views

Why is mercury a “fancy proton”?

I remember that one of my old organic chemistry profs referred to mercury as being a "fancy proton". I think it was in the context of oxymercuration reduction. What might have been his rationale for ...
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1answer
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Why are peroxides explosive?

Why do peroxides tend to explode with little provocation? In general, what are typical products of their explosion?
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Adulteration of turmeric with Metanil yellow

I read in the local paper that common food products like turmeric can be adulterated. It continued to specify the adulterant which they called metanil yellow. On searching on the Net, I was able to ...
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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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How to name this cyclic compound with an O in it?

How to name this cyclic compound with an O in it? I was going to name it cyclobutane, but not all of the atoms making up the ring are carbons, one is an oxygen. So, then I decided to name it butane, ...
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How does brewing time and brewing temperature affect the flavonoid concentration of green tea?

I've searched a lot for this, but I still cannot find any good explanations for how these two factors affect flavonoid concentrations.
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How does temperature affect the concentration of flavonoids in orange juice?

I am in high school, and I would like to do an experiment on this for a project. I've done quite a bit of research into the different methods I could use (see 2.4.2 here) but I still cannot find ...
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67 failures at extracting acetaminophen from Excedrin(R)

I have adapted the lab experiment described in this J. Chem. Ed. article for the organic chemistry lab course I teach. In the past year, the first year of implementation, I have had 67 failures (100% ...
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Energy-efficiency aside, what are the chemical constraints on CO₂ capture and methanation?

Synthesising $\ce {CH4}$ from air and water (in a non-biological process) has been proposed as one form of energy storage. What are the chemical constraints at play here? That is to say, what sort of ...
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Why are many drugs in the hydrochloride form? [duplicate]

Possible Duplicate: Why are solid phase organics often conjugated to HCl? I'm wondering why a lot of drugs are in this hydrochloride form. E.g., Cetirizine hydrochloride Methylphenidate ...
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Synthesis of mandelic acid from benzaldehyde

For an upcoming exam, I have to describe the synthesis of 2-hydroxy-2-phenylacetic acid (mandelic acid) from benzaldehyde. The provided answers describe quite a long process, consisting of 8 stages. ...
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Synthesis of chloroquine from 4-amino-7-chloroquinoline

Can we get chloroquine from 4-amino-7-chloroquinoline (7-chloroquinolin-4-amine) by adding 4-chloro-N,N-diethylpentan-1-amine $(\ce{CH3CHCl(CH2)3N(Et)2})$ ?
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Activated Carbon - Desorption in sunlight?

I have some activated charcoal pads or small "pillows" that can be used to adsorb odors and chemical fumes from different materials. The instructions say to put them out in sunlight to reactivate ...
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1answer
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The Chemistry behind creating Polylactic Acid (PLA)

I've seen a few videos of persons creating plastics from starch by adding an acid, glycerol, and water, however no explanation of the chemistry. Does anyone know what $\ce{(C6H10O5)_{n} + C3H8O3 + ...
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Chemical compounds responsible for the colors in flowers?

I know that anthocyanins are a class of compounds responsible for the purple colors found in flower petals. Anthocyanins (also anthocyans; from Greek: ἀνθός (anthos) = flower + κυανός (kyanos) = ...
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Explain the nomenclature of 7-amino-4-methylcoumarin

Can someone explain the nomenclature of 7-amino-4-methylcoumarin, pictured below (from the Sigma-Aldrich website)? The alpha-carbons of the methyl- and amino-groups here are separated by a minimum of ...
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3answers
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Why do Magnesium and Lithium form *covalent* organometallic compounds?

Lithium and magnesium are Group 1 and Group 2 elements respectively. Elements of these groups are highly ionic, and I've never heard of them forming significantly covalent inorganic compounds. Yet ...
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By what reaction does (–)-sparteine decompose in ambient conditions?

In its pure form (–)-sparteine is an only-slightly-yellow clear, viscous liquid. Yet, after only a week of being kept in dry, normal atmosphere (in a round bottom flask covered by a septa), some of it ...
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1answer
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Is soap the natural form of Sodium Lauryl Sulfate?

I was told that "Sodium Tallowate, sodium cocoate and sodium palm kernelate are the 'natural' forms of SLS". Is this true? I thought "natural" SLS would be SLS derived from a natural product such as ...
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1answer
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How are $\sigma$ and $\sigma^\pm$ determined in Hammett plots?

The Hammett plot is commonly invoked in organic chemistry to reason about the plausibility (or implausibility) of various reaction mechanisms. The vertical axis is essentially the logarithm of an ...
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1answer
989 views

What is the difference between an angular and linear skeletal formula?

When drawing a skeletal formula, what is the difference between an angular version and a linear version? I was asked to draw the Z isomer of Resveratrol: For which I drew: However the markscheme ...
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1answer
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Why is the benzyne triple bond distorted?

In many places I've seen the "extra" bond in benzyne being labelled as $\ce{sp^2-sp^2}$ overlap or distorted (not parallel) $\ce{p\pi-p\pi}$ overlap. But I've failed to see why we can't have a normal, ...
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1answer
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Why do thiols have such a propensity for bonding with mercury?

Historically, thiols $\ce{-SH}$ were known as "mercapto-" due to their strong propensity to bond with mercury. Certain drugs still carry this designation, though mercaptopurine has an $\ce{=S}$ group ...
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What are the major factors that influence LogP

The partition coefficient is a very useful metric in characterizing compounds particularly drugs. What chemical properties influence that partitioning? Are chemical moieties additive in their LogP? ...
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Why does the sulfone ring in tazobactam open when the lactam is hydrolyzed?

One of the drugs I work with is a beta-lactam (4-membered ring with an amide bond) fused to a sulfone ring, tazobactam. It's relatively stable in water; the lactam is not significantly hydrolyzed ...
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What makes diazo compounds so unstable and explosive?

I once had an Orgo TA refer to a diazo compound as "diazo-boom-boom" (the technical term). I have always been curious as to the reason behind the instability and reactivity. According to Wikipedia ...
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How can we synthesize para-nitrophenol

During nitration of phenol, both para- and ortho-nitrophenols will be formed. Is there any way in which we can synthesize para-nitrophenol only?
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Why is benzyne an intermediate?

I've always seen benzyne (benzene with a triple bond) classified as an "intermediate". I really don't see why it needs to be an intermediate, though. The possible reasons I can come up with are flimsy:...
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What makes an epoxide stable?

Overall ring strain seems to be a big issue when it comes to organic chemistry. That is why cyclopentane may be in an "envelope form" or why cyclobutane may be in a kinked, kite form. Both of these ...
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Why is it that the bigger the side-chain is, its hydrogen atoms tend to be more equatorial?

The most stable cyclohexane form is the chair conformation but on the other hand, the bigger the side-chain of the cyclohexane is, its hydrogen atoms become more equatorial rather than axial, which ...
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How do you separate enantiomers?

There are some stereochemical reactions that result in the presence of enantiomers. When moving forward with a practical organic synthesis, how does one usually separate them in order to continue with ...
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Why are arenes with conjoined benzene rings drawn as they are?

Whilst we are taught to represent benzene as below (A) due to its delocalised electrons, however when two benzene rings share carbons (e.g. naphtalene) it seems to be more commonly represented in ...
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How large is the energy difference between keto- and enol-form of guanine and uracil?

The nucleobases in DNA and RNA are generally present in the keto-form, and not in the enol-form. As an interesting historical note, James Watson and Francis Crick did initially believe them to adopt ...
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During the development of aspartame, why was the methyl ester chosen?

One frequent argument against the safety of the synthetic sweetener aspartame is that it can be hydrolyzed, with one of the hydrolysis products being methanol, which is known to be toxic. Of course, ...
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Mechanism of arene side chain oxidation by permanganate

When treated with hot, concentrated acidic $\ce{KMnO4}$, arenes are oxidised to the corresponding carboxylic acids. For example, toluene is oxidised to benzoic acid. I've tried to examine how this ...
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What can I do if I don't get a phase separation between my organic and water phases?

Solvent extraction in a separation funnel is a very common method in preparative organic chemistry. But sometimes you don't get a nice phase separation between the organic and the water phase. What ...
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1answer
379 views

How does the choice of metal (oxide) catalyst affect the range of unsaturated compounds that can be hydrogenated?

In the hydrogenation of unsaturated compounds with hydrogen gas and a catalyst, the choice of palladium on carbon is able to hydrogenate alkenes and alkynes, but is unable to hydrogenate aromatic ...
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Acid catalysed synthesis of ethyl ethoxymethylenemalonate

One synthesis of quinolones begins with the formation of an ethyl ethoxymethylenemalonate, as seen in this Organic Syntheses paper. I've been asked if the malonate derivative would be formed if ...
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Michael reaction or nucleophilic attack at the alpha carbon of an alpha-beta-unsaturated ketone?

What conditions promote a nucleophile to undergo the Michael reaction over the nucleophilic attack at the alpha carbon of the carbonyl group in an alpha-beta-unsaturated ketone? I'm looking for an ...
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385 views

Can recent developments improve the total synthesis of B-12?

The total synthesis of vitamin B-12 by Robert Burns Woodward and Albert Eschenmoser, is over 30 years old. At its time, it was considered a landmark in the field. With current developments (e.g. ...
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1answer
440 views

Precedence of 1,2 carbocation rearrangement

How can one choose which group has more shifting tendency in 1,2 carbocation rearrangement? The obvious order is via the stability of the carbocation of the group. But, phenylic groups have high ...
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Is activated carbon classified as organic or inorganic?

Organic compounds are typically defined as “molecules containing carbon”. Wikipedia states that there for some historical (read: non-logical) reasons, a few types of carbon-containing compounds ...