Question

Convert 1- bromobutane to hex - 1 yne​

Answer 1

Answer:

Though but-2-ene is more stable than but-1-ene it's still possible to convert them into each other easily as follows:

Add HBrHBr into but-2-ene solution it will result in formation of 2-bromobutane.

reaction equation of HBr addition to but-2-ene

Now add C(CH3)OKC(CHX3)OK to the obtained 2-bromobutane, as it is a bulky base, due to steric factors it forms the Hoffman product via a Hoffman elimination reaction

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Sorry that the second picture is not the perfect representation, but it still should aid understanding.

Answer 2

1-bromo butane can be converted into hex-1-yne by treating it with sodium acetylide in non polar solvents like ether.

• The hydrogen in acetylene is acidic so, acetylene when heated with sodium produces sodium acetylide.
• Sodium acetylide in non-polar solvents performs a second order substitution reaction upon 1-bromo butane in which the bromide group is substituted by the acetylide ion giving rise to hex-1-yne.