An organic compound CH _3 -CH=CH-CH _2 -CHO is taken in two different containers A and B. Sample in A is treated with H _2 / Ni forming new compound P. Sample in B is treated with LiAlH _4 and hydrolyzed further forming new compound Q. Identify P and Q.
D. P = CH _3( CH _2)_3 CH _2 OH and Q = CH _3 -CH=CH-CH _2 -CH _2 OH
The given organic compound is CH _3 -CH=CH-CH _2 -CHO . When treated with H _2 in the presence of Ni catalyst, both the carbon-carbon double bond and the aldehyde group are reduced. The alkene is reduced to an alkane and the aldehyde is reduced to a primary alcohol. Thus, the product P is pentan-1-ol, which is CH _3( CH _2)_3 CH _2 OH . When treated with LiAlH _4 followed by hydrolysis, only the aldehyde group is reduced to a primary alcohol. LiAlH _4 does not reduce isolated carbon-carbon double bonds. Thus, the double bond remains intact and the product Q is pent-3-en-1-ol, which is CH _3 -CH=CH-CH _2 -CH _2 OH . Therefore, P = CH _3( CH _2)_3 CH _2 OH and Q = CH _3 -CH=CH-CH _2 -CH _2 OH . Answer: P = CH _3( CH _2)_3 CH _2 OH and Q = CH _3 -CH=CH-CH _2 -CH _2 OH
Related: Chemistry — Aldehydes and Ketones · All PYQ Banks