(R)-Butan-2-ol is treated with SOCl2 alone, without pyridine (SNi mechanism with retention). The product is

JEE Main levelSingle correct optionDifficulty 2 of 3hx208

(R)-Butan-2-ol is treated with $SOCl X_{2}$ alone, without pyridine (SNi mechanism with retention). The product is

In SNi the chlorosulfite collapses with Cl delivered to the same face, so the configuration is retained. Priority order is OH >

C X_{2} H X_{5}

CH X_{3}

> H and Cl >

C X_{2} H X_{5}

CH X_{3}

> H, so the label remains R.