wittig explain

32 Answers

1
skygirl ·

yes srinath ... dats my doubt as well.... :)

1
skygirl ·

pata nahi kaise upar wala carbon pe attack hoga aur kyun hoga [12] ....

11
Sunil Kumar ·

Bas Yaar bahut huaa mere dimaag ne iss topic par sochnaa band kar diya ab.........
Lagta book kholni hi padegi.......

1
vector ·

IN ANS D MECHANISM PROPOSED IS SAME AS SKY BUT IN 1ST STEP ATTACK ON D UPPER WALA CARBON

1
skygirl ·

no yaar... betain intermediate forms because : P=O bond is srtonger than P=CH2.

11
Sunil Kumar ·

@sky.
Here the compound is not having carbonyl group.
My 3rd step structure is somewhat similar to BETAIN INTERMEDIATE.

1
skygirl ·

there is BETAIN INTERMEDIATE in the mechanism ...

here no such thing is there...

11
Sunil Kumar ·

well if u go according to wittig's rxn mechanism, P shud attack but i don't know clearly about this..........

1
vector ·

REPLY

1
vector ·

@ sunil acc to me due to double bond in conjugation where u have shown c- in 1st step it would be c+ n attack must be done by c of c-pph3

1
vector ·

no sky d ques is correct

1
skygirl ·

arey toh maine bhi toh daali .... i mean zor!! [3]

11
Sunil Kumar ·

iskaa matlab khaaali peeeli dimaag par itna zor dala maine aur ye banaya.....
Richa pls check the question.

1
skygirl ·

and i thnk... the reactant shud have =O in place of =CH2 .

richa plz chcek...

1
skygirl ·

no dhruv ,,, e-density is not high on P ...

i did that coz PPh3 is a good leaving group...

1
neil.dhruva ·

i think sky is right..most prob due to high e- density on P, CH2 attacks on C and not P..

11
Sunil Kumar ·

richa i think this might be the mechanism.
I'm not quite sure........

1
voldy ·

richa are you sure of the question ?

11
Sunil Kumar ·

Sky, I've problem in ur 2nd step.... Shouldn't the -ve charge on CH2 Should attack on +vely charged P....

In my 4th step, actually due to more crowd there the bond bwtween Ph3P and CH2 breaks and the resulant product is formed.............

1
skygirl ·

i have doubt wid your 4th step sunil...

i basically cudn understant wat happened there...

1
skygirl ·

1
skygirl ·

but is this wittig reaction?? [7] [7] [12]

in wittig there's =O in the reactant ...

and last which forms Ph3P=0 .

33
Abhishek Priyam ·

:)

mehant ka fal mitha hota hai...

11
Sunil Kumar ·

mehnat kahan nahi lagti....... Likhne me bhi mehnat lagti hai.........
yaar scanner hai nahi aur mobile ka camera vga hai, isliye banana hi padta hai paint par.........

33
Abhishek Priyam ·

bahut mehnat se banaya hoga... sunil.. :)

3
msp ·

yup sunil i cant find ne flaw in ur mech.

33
Abhishek Priyam ·

lag to raha hai...

it was asked to give mech for the product and u are getting product... :)

so correct to me.. :)

11
Sunil Kumar ·

@priyam. Mechanism sahi hai........

33
Abhishek Priyam ·

sunil.. gr8

1
Amit Jha ·

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