Skip to main content

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.

Filter by
Sorted by
Tagged with
6 votes
1 answer
1k views

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 ...
Adi's user avatar
  • 547
22 votes
3 answers
3k views

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% ...
Ben Norris's user avatar
  • 42.9k
10 votes
0 answers
198 views

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 ...
Pascal Qyy's user avatar
15 votes
1 answer
6k views

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. ...
avramov's user avatar
  • 335
6 votes
3 answers
12k views

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 $(\ce{CH3CHCl(CH2)3N(Et)2})$ ?
Rafael Adel's user avatar
15 votes
1 answer
11k views

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 ...
Casper's user avatar
  • 375
8 votes
1 answer
21k views

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 + ...
user avatar
21 votes
2 answers
7k views

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) = ...
Janice DelMar's user avatar
10 votes
2 answers
2k views

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 ...
Drew Steen's user avatar
17 votes
3 answers
26k views

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 ...
ManishEarth's user avatar
  • 15.2k
18 votes
2 answers
2k views

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 ...
Brad's user avatar
  • 181
3 votes
1 answer
4k views

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 ...
jrennie's user avatar
  • 141
14 votes
1 answer
9k views

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 ...
Jiahao Chen's user avatar
  • 2,653
9 votes
1 answer
1k 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 ...
Rory's user avatar
  • 785
13 votes
1 answer
2k views

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, ...
ManishEarth's user avatar
  • 15.2k
26 votes
1 answer
5k views

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 ...
jonsca's user avatar
  • 2,977
12 votes
2 answers
19k views

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? ...
bobthejoe's user avatar
  • 2,400
17 votes
1 answer
1k views

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 ...
Nick T's user avatar
  • 2,563
26 votes
2 answers
4k views

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 ...
jonsca's user avatar
  • 2,977
12 votes
3 answers
8k views

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?
Eka's user avatar
  • 2,758
13 votes
2 answers
3k views

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:...
ManishEarth's user avatar
  • 15.2k
22 votes
3 answers
7k views

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 ...
Cardtrick's user avatar
  • 965
9 votes
1 answer
315 views

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 ...
Khaloymes's user avatar
  • 191
29 votes
3 answers
67k views

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 ...
Cardtrick's user avatar
  • 965
19 votes
3 answers
2k views

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 ...
Rory's user avatar
  • 785
19 votes
2 answers
2k views

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 ...
Mad Scientist's user avatar
20 votes
4 answers
2k views

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, ...
user avatar
49 votes
1 answer
30k views

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 ...
ManishEarth's user avatar
  • 15.2k
25 votes
3 answers
2k views

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 ...
Mad Scientist's user avatar
14 votes
1 answer
419 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 ...
user avatar
15 votes
1 answer
5k views

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 ...
CHM's user avatar
  • 2,638
26 votes
2 answers
7k views

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 ...
LanceLafontaine's user avatar
15 votes
2 answers
511 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. ...
PKG's user avatar
  • 271
21 votes
1 answer
566 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 ...
ManishEarth's user avatar
  • 15.2k
30 votes
3 answers
10k views

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 ...
F'x's user avatar
  • 23.8k
18 votes
1 answer
1k views

Stability of organophosphorous vs organophosphates?

In environmental chemistry, most of the organophosphorous compounds we worry about are actually organophosphate compounds. Is there something about the $\ce{C-P}$ bond that makes it less stable (and ...
Pat's user avatar
  • 1,050
48 votes
2 answers
17k views

Why does nitration of N,N-dimethylaniline occur at the meta position?

The nitration of N,N-dimethylaniline with $\ce{H2SO4}$ and $\ce{HNO3}$ gives mainly the meta product, even though $\ce{-NMe2}$ is an ortho,para-directing group. Why is this so?
Andrew's user avatar
  • 2,322
18 votes
1 answer
11k views

How does Polytetrafluoroethylene (Teflon) differ from Polyvinylidene fluoride (PVDF) as a protein binding membrane material?

PTFE and PVDF (durapore) are both used in protein binding filter membranes (Millipore specifically). Chemically speaking the two polymers differ quite significantly due to the additional fluorides and ...
bobthejoe's user avatar
  • 2,400

1
204 205 206 207
208