Question

Convert but 2 ene to but 1 ene

Answer 1

Answer:

hope

Explanation:

Well one way is by addition followed by elimination.

You can add acrossH2O(pass steam over hot pumice) toCH3CH=CHCH3to formCH3CH2CH(OH)CH3, which can undergo elimination to yield two products but-1-ene (minor) and but-2-ene (major) (to eliminate, add conc.H2SO4). However, the yield is not so great but it works!

Another way is by hydrogenating it followed by halogenation and finally elimination. You first hydrogenate it by passingH2overNicatalyst under heat and pressure, followed by addition of a halogen (preferably chlorine) by free radical substitution (UV at RTP) followed by elimination by refluxing it with ethanolic conc. Alkali (likeNaOH) to get your desired product. Remember that the free radical substitution will yield a variety of products but preferentially more Cl at the 1st carbon position than in the second.

Hope this HELPS!!

Answer 2

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 HBr 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)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.

Explanation: