Reaction Pathways HELP (1 Viewer)

[csi]

Does anyone know how to do the attached questions? Any help is appreciated. Thanks!

 

[edds7575]

Does anyone know how to do the attached questions? Any help is appreciated. Thanks!

For the first question, starting from but-1-ene, I think you add hydrogen (hydrogenation reaction) with a metal catalyst and heat to produce butane. Then add the chlorine under UV light (substitution reaction) to produce 1-chlorobutane. Subsequently, react the 1-chlorobutane with sodium hydroxide under heat (substitution reaction) to produce butan-1-ol. Add acidified potassium permanganate to oxidise the butan-1-ol to butanoic acid. Then react the butanoic acid with potassium hydroxide (acid-base reaction) to produce potassium butanoate.

For the second question, I think you could mostly use the same pathway, but instead of going through a hydrogenation reaction and then a substitution reaction, you could simply add hydrochloric acid (HCl). (not sure if concentrated or dilute)

I'm not sure how to do the third question, maybe someone else can help or suggest a better pathway?

 

[csi]

For the first question, starting from but-1-ene, I think you add hydrogen (hydrogenation reaction) with a metal catalyst and heat to produce butane. Then add the chlorine under UV light (substitution reaction) to produce 1-chlorobutane. Subsequently, react the 1-chlorobutane with sodium hydroxide under heat (substitution reaction) to produce butan-1-ol. Add acidified potassium permanganate to oxidise the butan-1-ol to butanoic acid. Then react the butanoic acid with potassium hydroxide (acid-base reaction) to produce potassium butanoate.

For the second question, I think you could mostly use the same pathway, but instead of going through a hydrogenation reaction and then a substitution reaction, you could simply add hydrochloric acid (HCl). (not sure if concentrated or dilute)

I'm not sure how to do the third question, maybe someone else can help or suggest a better pathway?

Thank you!

 

[CM_Tutor]

For the second part, they are looking for a hydration of but-1-ene to make butanol as the first step. The problem (part (c)) is that the hydration reaction follows Markovnikov's Rule and so the major product of hydration is butan-2-ol (which oxidises to butanone) rather than butan-1-ol, which oxidises to butanoic acid.

The way around the problem (not covered by the HSC, though) is to do the hydration using borane, which goes via an anti-Markovnikov addition:

3 CH₃CH₂CH=CH₂ + BH₃ -------> B(CH₂CH₂CH₂CH₃)₃

B(CH₂CH₂CH₂CH₃)₃ + 3 H₂O₂ ---H₂O----> 3 CH₃CH₂CH₂CH₂OH + B(OH)₃

Note that there is also a problem with the first pathway as radical chlorination of butane will yield a substantial amount of 2-chlorobutane as well as the desired 1-chlorobutane, not to mention dichlorobutane and trichlorobutane and so on products.

 

[csi]

For the second part, they are looking for a hydration of but-1-ene to make butanol as the first step. The problem (part (c)) is that the hydration reaction follows Markovnikov's Rule and so the major product of hydration is butan-2-ol (which oxidises to butanone) rather than butan-1-ol, which oxidises to butanoic acid.

The way around the problem (not covered by the HSC, though) is to do the hydration using borane, which goes via an anti-Markovnikov addition:

3 CH₃CH₂CH=CH₂ + BH₃ -------> B(CH₂CH₂CH₂CH₃)₃

B(CH₂CH₂CH₂CH₃)₃ + 3 H₂O₂ ---H₂O----> 3 CH₃CH₂CH₂CH₂OH + B(OH)₃

Note that there is also a problem with the first pathway as radical chlorination of butane will yield a substantial amount of 2-chlorobutane as well as the desired 1-chlorobutane, not to mention dichlorobutane and trichlorobutane and so on products.

Thank you!!!