Monday, 21 September 2015
REIMER-TIEMANN REACTION:-
The Reimer-Tiemann reaction is an organic reaction used to convert a phenol to an o-hydroxy benzalde-hyde using chloroform, a base, and acid work-up. The mechanism begins with abstraction of the proton from chloroform with the base to form a trichlorocarbanion which spontaneously loses a chloride ion to form a neutral dichlorocarbene. The base also deprotonates the phenol reagent which then attacks the carbene. A series of steps and a final acid work-up result in the o-hydroxy benzaldehyde product.
AMINO ACIDS:-
Amino acids are biologically important organic compounds made from amine (-NH2) and carboxylic acid (-COOH) functional groups, along with a side-chain specific to each amino acid. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen, though other elements are found in the side-chains of certain amino acids. About 500 amino acids are known and can be classified in many ways. Structurally they can be classified according to the functional groups' locations as alpha- (α-), beta- (β-), gamma- (γ-) or delta- (δ-) amino acids; other categories relate to polarity, pH level, and side chain group type (aliphatic, acyclic, aromatic, containing hydroxyl or sulfur, etc.) In the form of proteins, amino acids comprise the second largest component (after water) of human muscles, cells and other tissues.Outside proteins, amino acids perform critical roles in processes such as neurotransmitter transport and biosynthesis.
SAWHORSE AND NEWMAN PROJECTIONS:-
A Newman projection, useful in alkane stereochemistry, visualizes chemical conformations of a carbon-carbon chemical bond from front to back, with the front carbon represented by a dot and the back carbon as a circle (see below). The front carbon atom is called proximal, while the back atom is called distal. This type of representation is useful for assessing the torsional angle between bonds.
ARNDT-EISTERT SYNTHESIS....
(reaction to increase a carbon in carbon chain)
The Arndt-Eistert Synthesis allows the formation of homologated carboxylic acids or their derivatives by reaction of the activated carboxylic acids with diazomethane and subsequent Wolff-Rearrangement of the intermediate diazoketones in the presence of nucleophiles such as water, alcohols, or amines.
The Arndt-Eistert Synthesis allows the formation of homologated carboxylic acids or their derivatives by reaction of the activated carboxylic acids with diazomethane and subsequent Wolff-Rearrangement of the intermediate diazoketones in the presence of nucleophiles such as water, alcohols, or amines.
Saturday, 12 September 2015
What Is Organic Chemistry?
Words are funny things. A
word that means one thing to one person might mean something completely
different to another person. In the United States the word football refers
to a game played with an oval-shaped ball that players pass with their hands or
hold with their hands while they run with it. In England football refers
to a game played with a round ball that players kick with their feet. (In the
United States people call this game soccer.)
The word organic is
another word that means different things to different people. To many people organic means
“natural.” For example, gardeners sometimes talk about using organic
fertilizer. What they mean is that they’re putting something natural like
compost or manure on their plants instead of human-made, or synthetic,
fertilizers.
Organic means something completely different to chemists.
In chemistry organic means “carbon-based.” To a chemist, an
organic compound is any compound that contains carbon. That is, an organic
compound is any compound whose molecules contain carbon atoms. All
living things are made of compounds containing mostly carbon, so lots of things
that are “organic” to a gardener are also “organic” to a chemist.
Of course, there are many
carbon compounds that are human-made, or synthetic. To chemists, these are
organic compounds too. Plastics are organic, and so are most synthetic wonder
drugs, as far as chemists are concerned. They are organic because they are
carbon-based. Chemists would even say most of the synthetic fertilizers, the
ones that “organic” gardeners don’t use, are organic too. This is because
synthetic fertilizers are made of molecules that are made of mostly carbon
atoms.
In fact, most chemists
laugh a little when they see the word organic on food packages
in the grocery store. All food is made of carbon-based molecules, and so are
most food additives, whether they’re natural or synthetic. So to a chemist, all
food is “organic.”
So when we talk about “organic chemists,” we’re not talking about chemists who only use all-natural substances. We’re talking about chemists who make and study compounds that are made of carbon, whether the compounds are natural or synthetic.
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