Chemistry-
General
Easy
Question
Karl Ziegler reported that alkenes react with N-bromosuccinimide (NBS) in presence of light to give products resulting from substitution of hydrogen by bromjne at the allylic position, i.e., the position next to the double bond. Let us consider the halogenation of cyclohexene.
Energy level diagram for allylic, vinylic and alkylic, free radicals is .given below:
In the treatment of cyclohexene with NBS, which of the following products will be least stable?
- Cannot be predicted
The correct answer is:
Related Questions to study
Chemistry-
The high reactivity of alkyl halides can be explained in terms of nature of C-X bond which is highly polarised covalent bond due to large difference in the electronegativities of carbon and halogen .atom. This polarity is responsible for the nucleophilic substitution reactions of alky- halides which mostly occur by 
and 
mechanisms reaction is a two step process . and in the first step, R-X ionises to give carbocation (slow process). In the second step, the nucleophile attacks the carbocation from either side to form the product (fast process). In reaction, there can be racemization and inversion. reaction is favoured by heavy (bulky) groups on the carbon atom attached to halogens. i.e., 
In reaction, the strong nucleophile OH- attacks from the opposite side of the chlorine atom to give an intermediate (transition state). which breaks to yield the product (alcohol) and leavj.ng 
group. The alcohol has a configuration opposite to drat 'of the bromide and is said to proceed with inversion of configuration. reaction is favoured by small groups on the carbon atom attached to halogen i.e., 
The main product formed in the following reaction is:
The high reactivity of alkyl halides can be explained in terms of nature of C-X bond which is highly polarised covalent bond due to large difference in the electronegativities of carbon and halogen .atom. This polarity is responsible for the nucleophilic substitution reactions of alky- halides which mostly occur by and mechanisms reaction is a two step process . and in the first step, R-X ionises to give carbocation (slow process). In the second step, the nucleophile attacks the carbocation from either side to form the product (fast process). In reaction, there can be racemization and inversion. reaction is favoured by heavy (bulky) groups on the carbon atom attached to halogens. i.e.,
In reaction, the strong nucleophile OH- attacks from the opposite side of the chlorine atom to give an intermediate (transition state). which breaks to yield the product (alcohol) and leavj.ng group. The alcohol has a configuration opposite to drat 'of the bromide and is said to proceed with inversion of configuration. reaction is favoured by small groups on the carbon atom attached to halogen i.e.,
The main product formed in the following reaction is:
Chemistry-General
Chemistry-
Compound 
undergoes intramolecular nucleophilic substitution of the type .... giving .
Compound undergoes intramolecular nucleophilic substitution of the type .... giving .
Chemistry-General
Chemistry-
In the following compounds, nucleophile and the leaving groups are in the same molecule:
I) 
II) 
III) 
IV) 
These dual nature species can undergo intramolecular and intermolecular nucleophilic substitution. Intramolecular substitution reaction is possible in:
In the following compounds, nucleophile and the leaving groups are in the same molecule:
I)
II)
III)
IV)
These dual nature species can undergo intramolecular and intermolecular nucleophilic substitution. Intramolecular substitution reaction is possible in:
Chemistry-General
Chemistry-
Ullmann reaction is given by:
Ullmann reaction is given by:
Chemistry-General
Chemistry-
The major product of the reaction,
with HBr is:
The major product of the reaction,
with HBr is:
Chemistry-General
Chemistry-
The reaction given
is:
The reaction given
is:
Chemistry-General
Chemistry-
In the reaction,
the compound (C) is:
In the reaction,
the compound (C) is:
Chemistry-General
Chemistry-
The major product obtained in the reaction,
The major product obtained in the reaction,
Chemistry-General
Chemistry-
In which of the following reactions, an optically. active single product is formed?
In which of the following reactions, an optically. active single product is formed?
Chemistry-General
Chemistry-
When 
reacts with KOH in presence of water (through reaction mechanism) then stereochemistry of product so formed will be:
When reacts with KOH in presence of water (through reaction mechanism) then stereochemistry of product so formed will be:
Chemistry-General
Chemistry-
Which of the following is ,fast de-brominated?
Which of the following is ,fast de-brominated?
Chemistry-General
Maths-
If a, b, c are lengths of the sides of a triangle, then 
is
If a, b, c are lengths of the sides of a triangle, then is
Maths-General
Maths-
If a, b, c are +ve, then 
is
If a, b, c are +ve, then is
Maths-General
Maths-
3 distinct integers are selected at random from 1, 2, 3,…, 20. The probability that the sum is divisible by 5 is
3 distinct integers are selected at random from 1, 2, 3,…, 20. The probability that the sum is divisible by 5 is
Maths-General
Maths-
If 
, then
If , then
Maths-General
