Question

(a) draw structure of following:
(1) cyanohydrin of cyclobutanone.
(2) hemiacetal of ethanal.
(b) write the major products in the following:
(1) Ch3 -ch = ch - ch2 - cn (in presence of DIBAL -H and H3O+) this gives ?
(2) Ch3- ch2 - OH (Cro3) this gives ?
(c) how can you distinguish between propanal and propanone?

Answer 1

Answer: for 2 part of the question

b 1 CH3CH2OH ---------CH3CH2CHO

Oxidation of alcohol

Ch3Ch=CHCH2CN ---------CH3CH=CHCH2CHO

c.propanal - positive test for Fehling or tollens reagent

Propane - positive iodoform test

{Give the equation for the reaction

c.

Explanation:

Answer 2

a) 1), 2) Structures of the reaction are given below in the attachment.

b) The major products in:

1) Ch3 -ch = ch - ch2 - cn (in presence of DIBAL -H and H3O+) is                         3 Pentene Aldehyde.

2)  Ch3- ch2 - OH (Cro3) is Ethanoic Acid.

c) Propanal and Propanone are reacted with Ammonical Silver Nitrate   (Tollen's reagent), Propanal being an aldehyde forms a silver mirror on the walls of container by reacting with the reagent, whereas Propanone won't give the reaction.