Phenol formation through biotransformation , involving Cytochrome P450E1, although the hydroxyl radical hydroxyaltes benzene to yield phenol. But, the hydroxyl radical derives from hydrogen peroxide. Pheno formation can only then occur, through hydroxyl radical-mediated formation, involving addition of a hydroxyl radical to the benzene ring. Perhaps this is 2 or even 3 steps?
Benzene + a hydroxyl radical = phenol.

There is an alternative mechanism which involes a two step process, in which benzene oxide is the first product, which can reaarrange non-enzymatically to form phenol, it is known as the Benzene oxide-oxepin system.

(edited 6 years ago)

Reply 4

Kalabamboo

OP

14

Original post by Science99999

Phenol formation through biotransformation , involving Cytochrome P450E1, although the hydroxyl radical hydroxyaltes benzene to yield phenol.
Benzene + a hydroxyl radical = phenol.

There is an alternative mechanism which involes a two step process, in which benzene oxide is the first product, which can reaarrange non-enzymatically to form phenol, it is known as the Benzene oxide-oxepin system.

I am still a bit confused. Could you please explain it to me in A level standard? would be much appreciated

Reply 5

Dat1Guy

16

Interesting yes. Well we know phenyl amine has to be made from benzene nitrate which is made from benzene, not 1 step.
Phenol can be made from substitution from chlorobenzene, so this is also not 1 step.
Benzoic acid can be made in friedel-crafts acylation and then you'd have to remove the methyl group and substitute in an -OH group, hence more than 1 step, and methylbenzene, friedel-crafts alkylation, which will not require a 2nd 'major step'

(edited 6 years ago)

Reply 6

Dat1Guy

16

Original post by Science99999

Phenol formation through biotransformation , involving Cytochrome P450E1, although the hydroxyl radical hydroxyaltes benzene to yield phenol. But, the hydroxyl radical derives from hydrogen peroxide. Pheno formation can only then occur, through hydroxyl radical-mediated formation, involving addition of a hydroxyl radical to the benzene ring. Perhaps this is 2 or even 3 steps?
Benzene + a hydroxyl radical = phenol.

There is an alternative mechanism which involes a two step process, in which benzene oxide is the first product, which can reaarrange non-enzymatically to form phenol, it is known as the Benzene oxide-oxepin system.

What about substituting in -OH from chlorobenzene, which is more easily formed?

Reply 7

username2337287

14

Original post by Kalabamboo

I am still a bit confused. Could you please explain it to me in A level standard? would be much appreciated

The initial metabolic pathway for benzene biotransformation begins with phenol formation. Cytochrome P450/2E1 can produce hydrogen peroxide when acting as an oxidase of Nicotinamide adenine dinucleotide phosphate (NADPH). NADPH is a cofactor used in anabolic reactions such as lipid and nucleic acid synthesis, donating electrons (reducing agent) and hydrogen atoms . The hydroxyl radicals formed from hydrogen peroxide can hydroxylate benzene to yield phenol, through hydroxyl radical-mediated phenol formation, involving addition of a hydroxyl radical to the benzene ring. Phenol formation may also occur during rearrangement of benzene oxide.

Im in year 12: This was my essay I made regarding Benzene Oxidase: An enzyme which causes the transfer of a hydrogen atom from a specific substrate to an oxygen molecule, forming water or hydrogen peroxide.

Reply 8

username2337287

14

Original post by BDunlop

Interesting yes. Well we know phenyl amine has to be made from benzene nitrate which is made from benzene, not 1 step.
Phenol can be made from substitution from chlorobenzene, so this is also not 1 step.
Benzoic acid can be made in friedel-crafts acylation and methylbenzene, friedel-crafts alkylation..there must be some difference in the relative ease of forming methylbenzene over acylation of benzene, else i can't think how it could be '1 step' over acylation.