1.

Which of the following reactions will give alkyne

Answer»

`CH_3CH_2undersetunderset(Cl)|CH-undersetunderset(Cl)|CH_2underset(NaNH_2)OVERSET(H_2O)to`
`CH_3CH_2CHBr_2 undersetDeltaoverset"ALC KOH"to `
`CH_3-undersetunderset(Br)|oversetoverset(Br)|C-undersetunderset(Br)|oversetoverset(Br)|C-CH_3 overset"Zn/alcohol"to `
Potassium maleate `overset"electrolysis"to`

Solution :`CH_3CH_2underset"Cl"underset|CH-underset"Cl"underset|CH_2underset((ii)H_2O)overset((i)NaNH_2)to` give first `CH_3CH_2C-=overset thetaCNa^(+)NH_3`
`CH_3CH_2C-=oversetthetaCNa^(+) + H - OH to CH_3CH_2C-=CH+Na^(+)+OH^(-)`
Hence in (a) alkyne is formed.
`CH_3CH_2CHBr_2 undersetDeltaoverset"alc.KOH"to CH_3CH_2C-=CH`
This is againa dehydrohalogenation reaction. Hence (b) GIVES alkyne.
`CH_3-undersetunderset"Br"|oversetoverset"Br"|C-undersetunderset"Br"|oversetoverset"Br"|C-CH_3undersetDeltaoverset"Zn+alc."to CH_3-C-=C-CH_3`
Hence (c ) gives alkyne. Potassium maleate on electrolysis gives `CH-=CH` which is again alkyne. Hence (d) is CORRECT


Discussion

No Comment Found

Related InterviewSolutions