' x ' is the product which is obtained from propanenitrile and stannous chloride in the presence of hydrochloric acid followed by hydrolysis. ' y ' is the product which is obtained from the but-2-ene by the ozonolysis followed by hydrolysis. From the following, which product is not obtained when one mole of ' x ' and one mole of ' y ' react with each other in the presence of alkali followed by heating?
D. 3-Methylbut-2-enal
Product x is obtained by the Stephen reduction of propanenitrile (CH_3CH_2CN). CH_3CH_2CN SnCl_2/HCl CH_3CH_2CH=NH H_2O CH_3CH_2CHO (Propanal). Product y is obtained by the reductive ozonolysis of but-2-ene (CH_3CH=CHCH_3). CH_3CH=CHCH_3 O_3, H_2O/Zn 2CH_3CHO (Ethanal). When propanal (x) and ethanal (y) react in the presence of alkali followed by heating, they undergo cross-aldol condensation. Possible products are: 1. Self-aldol of propanal: CH_3CH_2CHO + CH_3CH_2CHO CH_3CH_2CH=C(CH_3)CHO (2-Methylpent-2-enal). 2. Self-aldol of ethanal: CH_3CHO + CH_3CHO CH_3CH=CHCHO (But-2-enal). 3. Cross-aldol (Ethanal as nucleophile): CH_3CH_2CHO + CH_3CHO CH_3CH_2CH=CHCHO (Pent-2-enal). 4. Cross-aldol (Propanal as nucleophile): CH_3CHO + CH_3CH_2CHO CH_3CH=C(CH_3)CHO (2-Methylbut-2-enal). Comparing with the options, 3-Methylbut-2-enal is not formed in any of these reactions.
Related: Chemistry — Aldehydes and Ketones · All PYQ Banks