(S)-Pentan-2-ol is converted into 2-chloropentane in two ways: with SOCl2 alone (route 1) and with SOCl2 in pyridine (route 2). Which statements are correct?

Route 1 gives (S)-2-chloropentane.

Route 2 gives (R)-2-chloropentane.

The chloride from route 2, treated with NaI in dry acetone (S_N2), gives (S)-2-iodopentane.

Route 1 gives (S)-2-chloropentane.

Route 2 gives (R)-2-chloropentane.

The chloride from route 2, treated with NaI in dry acetone (S_N2), gives (S)-2-iodopentane.

The chloride from route 1, treated with NaI in dry acetone (S_N2), gives (S)-2-iodopentane.

MolSynapse / Question bank / Haloalkanes and Haloarenes / Stereochemical outcomes of substitution

JEE Advanced levelOne or more correct optionsDifficulty 3 of 3hx054

(S)-Pentan-2-ol is converted into 2-chloropentane in two ways: with $SOCl X_{2}$ alone (route 1) and with $SOCl X_{2}$ in pyridine (route 2). Which statements are correct?

ARoute 1 gives (S)-2-chloropentane.
BRoute 2 gives (R)-2-chloropentane.
CThe chloride from route 2, treated with $NaI$ in dry acetone ( $S_{N} 2$ ), gives (S)-2-iodopentane.
DThe chloride from route 1, treated with $NaI$ in dry acetone ( $S_{N} 2$ ), gives (S)-2-iodopentane.

Answer: A, B, C

Route 1 is

S_{N} i

(retention), giving (S). Route 2 is inversion, giving (R). The order

X > C X_{3} H X_{7} > CH X_{3} > H

holds for alcohol, chloride and iodide. Iodide inverts: (R)-chloride gives (S)-iodide, so (c) is true, while the (S)-chloride from route 1 gives (R)-iodide, so (d) is false.

Practice Haloalkanes and Haloarenes More on Stereochemical outcomes of substitution

Previous questionNext question

(S)-Pentan-2-ol is converted into 2-chloropentane in two ways: with SOClX2​ alone (route 1) and with SOClX2​ in pyridine (route 2). Which statements are correct?

Answer: A, B, C

More questions on Stereochemical outcomes of substitution

(S)-Pentan-2-ol is converted into 2-chloropentane in two ways: with $SOCl X_{2}$ alone (route 1) and with $SOCl X_{2}$ in pyridine (route 2). Which statements are correct?