Single Choice

A partially racemised $$(+)-$$$$2$$$$-bromo-octane$$ ($$2^o\: RX$$) on reaction with aq. $$NaOH$$ in acetone gives an alcohol with $$80$$% inversion and $$20$$% racemisation. What is the percentage of front-side attack?

A$$10$$%
Correct Answer
B$$20$$%
C$$40$$%
D$$80$$%

Solution

The back side attack gives the inverted product whereas the front side attack gives product with same direction of polarization.
Let $$x$$ be fraction of front reaction and $$y$$ be fraction of back side reaction.
Given $$80$$% inversion and $$20$$% racemisation.
Fraction of racemic mixture= $$2x$$
Fraction of solely inverted product= $$y-x$$
$$2x=0.2 => x=0.1 or 10$$%
$$y=0.9$$ or $$90$$%

SIMILAR QUESTIONS

Haloalkanes and Haloarenes

A partially racemised (+)-$$2$$-bromo-octane ($$2^o $$RX) on reaction with aq. $$NaOH$$ in acetone gives an alcohol with $$80$$% inversion and $$20$$% racemisation. What is the percentage of back-side attack?

Haloalkanes and Haloarenes

Differentiate between retention and inversion.

Haloalkanes and Haloarenes

Give the stereochemical products of the following:

Haloalkanes and Haloarenes

Which of the following molecules have non-zero dipole moments ? (I) gauche conformation of $$ 1-2-$$ dibromethane (II) anti conformation of $$ 1, 2 $$dibromoethane (III) trans $$ -1,4- dibromocyclohexane $$ (IV) cis $$ -1, 4-$$ dibromocyclohexane (V) tetrabromomethane (VI) $$ 1, 1- $$ dibromocyclohexane

Haloalkanes and Haloarenes

The configuration of the carbon atom $$ C_2$$ and $$ C_3$$ in the following compound are, respectively:

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