Steric Hindrance

A third group is least likely to enter between two groups in the mta relationship. This is the result of steric hindrance and increases in importance with the size of the groups on the ring and with the size of the attaching species. When a meta-directing group is meta to an ortho-para directing group, the incoming group primarily goes ortho to the meta directing group rather than para. Q.

A third group is least likely to enter between two groups in the meta relationship. This is the result of steric hindrance and increases in importance with the size of the groups on the ring and with the size of the attacking species. When a Meat-directing group is meta to an ortho-para directing group, the incoming group primarily goes ortho th the meta directing group rather than para. Chlorination of m- chloro nitro benzene gives :

A third group is least likely to enter between two groups in the meta relationship. This is the result of steric hindrance and increases in importance with the size of the groups on the ring and with the size of the attacking species. When a Meat-directing group is meta to an ortho-para directing group, the incoming group primarily goes ortho th the meta directing group rather than para. overset(E^(+))rarr...... ?

Greater is the stability of the substituted ammonium cation, stronger should be the corresponding amine as a base. Thus, the order of basicity of aliphatic amines should be: primary > secondary > tertiary, which is opposite to the inductive effect based order. Secondly, when the alkyl group is small, like- CH_3 group, there is no steric hindrance to H-bonding. In case the alkyl group is bigger than CH_3 group, there will be steric hinderance to H-bonding. Therefore, the change of nature of the alkyl group, e.g.,from- CH_3 to- C_2 H_5 results in change of the order of basic strength. In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices. Assertion (A): Greater is the stability of the substituted ammonium cation, stronger is the corresponding amine as a base. Reason (R): The order of basicity of aliphatic amines is: primary > secondary > tertiary.

Nuclephilic substitution reaction is given by those compounds which have nucleophilic groups as leaving groups. The weaker the basicity of a group of the substrate, the better is its leaving ability. In nucleophilic substitution reactions, the basicity of leaving group should be less than the incoming nucleophilic group. Nucleophilc substitution reaction at sp^(3) -hybridised carbon is either bimolecular (S_(N^(2))) or unimolecular (S_(N^(1))) . Bimolecular reaction takes place in single step, involving transition state intermediate. In S_(N^(2)) reaction is preferred if the compound has less steric hindrance. Unimolecular (S_(N^(2))) reaction involves two steps and carbonium ion intermediate. Optically active substrates give recemic mixture in these reactions. S_(N^(2)) reaction involves transition state intermediate, hence it is favoured in which of the following solvents?

Nuclephilic substitution reaction is given by those compounds which have nucleophilic groups as leaving groups. The weaker the basicity of a group of the substrate, the better is its leaving ability. In nucleophilic substitution reactions, the basicity of leaving group should be less than the incoming nucleophilic group. Nucleophilc substitution reaction at sp^(3) -hybridised carbon is either bimolecular (S_(N^(2))) or unimolecular (S_(N^(1))) . Bimolecular reaction takes place in single step, involving transition state intermediate. In S_(N^(2)) reaction is preferred if the compound has less steric hindrance. Unimolecular (S_(N^(2))) reaction involves two steps and carbonium ion intermediate. Optically active substrates give recemic mixture in these reactions. Which among the following will give enantiomeric pair on treatment with HOH?