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For deprotection (regeneration of the alcohol) Aqueous base (pH >9) [6]; Aqueous acid (pH <2), may have to be heated [7]; Anhydrous base such as sodium methoxide in methanol. Very useful when a methyl ester of a carboxylic acid is also present in the molecule, as it will not hydrolyze it like an aqueous base would.
Ethylene glycol protects a ketone (as an acetal) during an ester reduction, vs. unprotected reduction to a diol. A protecting group or protective group is introduced into a molecule by chemical modification of a functional group to obtain chemoselectivity in a subsequent chemical reaction.
The carbonyl center of an acyl radical has one non-bonded electron with which it forms a chemical bond to the remainder (denoted with the letter R) of the molecule. The acetyl moiety is a component of many organic compounds , including acetic acid , the neurotransmitter acetylcholine , acetyl-CoA , acetylcysteine , acetaminophen (also known as ...
Generic structure of acetals. In organic chemistry, an acetal is a functional group with the connectivity R 2 C(OR') 2. Here, the R groups can be organic fragments (a carbon atom, with arbitrary other atoms attached to that) or hydrogen, while the R' groups must be organic fragments not hydrogen. The two R' groups can be equivalent to each ...
Hückel's rule can also be applied to molecules containing other atoms such as nitrogen or oxygen. For example, pyridine (C 5 H 5 N) has a ring structure similar to benzene, except that one -CH- group is replaced by a nitrogen atom with no hydrogen. There are still six π electrons and the pyridine molecule is also aromatic and known for its ...
Desulfonylation reactions are chemical reactions leading to the removal of a sulfonyl group from organic compounds.As the sulfonyl functional group is electron-withdrawing, [1] methods for cleaving the sulfur–carbon bonds of sulfones are typically reductive in nature.
However, in order for anomers to exist, the sugar must be in its cyclic form, since in open-chain form, the anomeric carbon atom is planar and thus achiral. More formally stated, then, an anomer is an epimer at the hemiacetal/hemiketal carbon atom in a cyclic saccharide. [1] Anomerization is the process of conversion of one anomer to the other.
In the latter case, two molecules of ketene combined with one molecule of an unsaturated compound (such as a quinone) to yield a six-membered ring. [71] While not a classic Diels-Alder reaction in the typical sense of a conjugated diene and a separate dienophile, Staudinger's observation of this [4+2] process, forming a six-membered ring ...