IIT JEE , AIEEE Forum - Chemistry , Organic Chemistry

sreeee

What is the intermediate in the Reiman teiman reaction?

Options are

Carbanion

Carbene

Phenoxide

None

I think it can be both A and C . But there is a confusing term ' intermediate'. Does it refer to all those species which are formed during the reaction mechanism. Actually the question was multiple choice and it asked which reaction proceeds through carbanion intermediate. Reiman tieman reaction was one of the option but surprisingly or (correctly?) the answer key says it is wrong.

Please help

khinart

An intermediate is a compound whose formation decides the feasibility of the reaction.Here a carbene is an intermediate as it is unstable and so the reaction proceeds in forward direction.

khinart

And if there is such a question that U are asking than yes there is a carbanion in the reaction also also the answer is reimer tiemann but if it is a single choice and it asks selectively for the intermediates than carbene is the answer.

catch_arnnie

yes, carbene is the rite answer...

madhusudan.chavan

Reimer-Tiemann reaction is an example of electrophilic substitution reaction. The electrophile in this case is dichlorocarbene which is obtained by the action of alkali on chloroform as follows:

Fast slow

HO^- + H¾CCl₃ ® H₂O + ^- CCl₃ ® : CCl₂ + Cl^?

Attack of dichlorocarbene on phenoxide ion results ultimately in the formation of benzal derivative which upon subsequent hydrolysis gives salicylaldehyde.

Formation of carbene is the slowest step hence it is the intermediate in the reaction.

bumba

yes carbene is the rite answer and phenoxide ion too.....

kuldud

yup sir is rite

its a dichloro carbene

but

the structure

is (CHCl2)C6H4(ONa)

plzz rate me

Ask & Discuss Questions with Community & Experts