2-Bromobutane is optically active but 1-Bromobutane is optically inactive. Why?
2-bromobutane is a chiral molecule as it contains an asymmetric carbon atom therefore, it is optically active whereas 1-bromobutane is an achiral molecule as it does not contain an asymmetric carbon atom therefore it is optically inactive.
Reaction of R-2-bromobutane with aqueous KOH follows two parallel reactions, one by SN2 (complete inversion) and other by SN1 (complete racemization). Specific optical activity for R-2-butanol is −13.50∘/gmL per dm length of the polarimeter.
If in a 10 cm tube polarimeter, 10 ml of R-2-bromobutane along with KOH is filled, then after complete reaction of R-2-bromobutane, the mass of all alcohols formed is found equal to 5 g of which 1 g is of R-2-butanol. Then, the total optical rotation (in degree) of the solution is
In the conversion of optically active (R) form of 2-chlorobutane to (R) form of 2-bromobutane, the following sequence of reactions is carried out.
Direct conversion is not feasible since Cl cannot be replaced by Br in one step.
In which of the following steps does the inversion occur?