91Ó°ÊÓ

Alcohols can be transformed into a strong nucleophile by generating its alkoxide ion. The O-H bond is cleaved when alcohol functions as a strong nucleophile or a weak nucleophile. The C-O bond is cleaved when alcohol reacts as an electrophile.

Tosylate esters indicated as ROTs are products acquired by the condensation of alcohol with p-toulenesulfonic acid. Tosylate groups are good leaving groups, and alkyl tosylates get subjected to substitution and elimination reactions like alkyl halides.

(a)Ethyl tosylate reacts with potassium tert-butoxide to generate two products. They are the substitution product at low temperature, and elimination product at high temperatures. The reaction can be given as

Reaction of ethyl tosylate with potassium tert-butoxide

The product obtained by elimination is the major product. Hence, ethane is formed as the major product.

(b) Isobutyl reacts with NaI to generate 1-iodo-2-methylpropane. The reaction can be given as:

Reaction of isobutyl tosylate and NaI

(c) (R)-2-hexyl tosylate reacts with NaCN generating (S)-2-methylhexanenitrile. The mechanism of this reaction follows an SN₂ mechanism. Hence, the product formed has an inversion of configuration. The reaction can be given as:

Reaction of (R)-2-hexyl tosylate with NaCN

(d)The tosylate of cyclohexanol reacts with one equivalent of ammonia to form an amine salt. If excess of ammonia is used, cyclohexylamine is formed. The reaction can be given as:

Reaction of the tosylate of cyclohexylmethanol with excess NH₃