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In chemistry, hydroxylation refers to the installation of a hydroxyl group (−OH) into an organic compound. Hydroxylations generate alcohols and phenols, which are very common functional groups. Hydroxylation confers some degree of water-solubility. Hydroxylation of a hydrocarbon is an oxidation, thus a step in degradation.
α-Hydroxylation with oxaziridines has been widely implemented in total synthesis. It is a key step in both the Holton Taxol total synthesis and the Wender Taxol total synthesis . Additionally, Forsyth implemented the transformation in his synthesis of the C3-C14 (substituted 1,7-Dioxaspiro[5.5]undec-3-ene) System of okadaic acid .
Hydroxyproline is produced by hydroxylation of the amino acid proline by the enzyme prolyl hydroxylase following protein synthesis (as a post-translational modification).The enzyme catalyzed reaction takes place in the lumen of the endoplasmic reticulum.
Expression of the recombinant protein demonstrated 7alpha-hydroxylation activity for steroids (DHEA, pregnenolone) and oxysterols including 25-hydroxycholesterol and 27-hydroxycholesterol, [9] [10] [11] confirmed by knockout in mouse that abolished oxysterol hydroxylation in liver [12] and brain and steroid hydroxylation in multiple tissues. [13]
These include hydroxylation, epoxidation of olefins, aromatic oxidation, heteroatom oxidations, N- and O- dealkylation reactions, aldehyde oxidations, dehydrogenation reactions, and aromatase activity. [17] [18] Hydroxylation of an sp 3 C-H bond is one of the ways in which CYP3A4 (and cytochrome P450 oxygenases) affects its ligand. [19]
Regarding the α-hydroxylation of carbonyls, the base first converts the ketone or ester into its corresponding enolate. Then, the enolate anion as a nucleophile attacks the oxygen atom of the oxaziridine in a S N 2 mechanism, forming a hemiaminal intermediate. The intermediate then fragments into a sulfinimine, and, after protonation, the ...
The Milas hydroxylation is an organic reaction converting an alkene to a vicinal diol, and was developed by Nicholas A. Milas in the 1930s. [ 1 ] [ 2 ] The cis-diol is formed by reaction of alkenes with hydrogen peroxide and either ultraviolet light or a catalytic osmium tetroxide , [ 3 ] vanadium pentoxide , or chromium trioxide .
The hydroxylation of estradiol is one of the major routes of metabolism of the estrogen steroid hormone estradiol. It is hydroxylated into the catechol estrogens 2-hydroxyestradiol and 4-hydroxyestradiol and into estriol (16α-hydroxyestradiol), reactions which are catalyzed by cytochrome P450 enzymes predominantly in the liver , but also in ...