[jena]

Hi,

My questions are:

1. 3-methylbutanoyl chloride + sodium 3-methylbutanoate=?

2. 3-methylbutanoic anhydride + methanamine=???

3. methyl 3-methylbutanoate + sodium hydroxide=???

4. N,3dimethylbutanamide + water, acid catalysis=???

5. sodium 3-methylbutanoate + hydrochloric acid=???

My answers:

1. 3-methylbutanoic anhydride, because Acyl Halide alkonyl halide plus a carboxylate salt will equal anhydride

2. N,3-dimethylbutanamide, my reasoning is that a anhydride with an amine will equal to an amide.

3. 3-methylbutanoic anhydride

4. methyl 3-methylbutanoate

5. Having problems with....


Please help and Thank You

[lemonoman]

sodium 3-methylbutanoate is a weak base, whereas hydrochloric acid is a strong acid.

Seems like an acid/base reaction, right?  It is  

But instead of the classic water-and-salt that you get from an OH^- base and H⁺ acid, you won't have that water (no OH^-).  You MAY however, have a salt forming.  Think about it...

[jena]

hi,

In reply to this question:

5. sodium 3-methylbutanoate + hydrochloric acid=???

Wouldn't the sodium 3-methybutanoate be considered a carboxylate salt. If it is then if I add an acid(HCl) to it wouldn't it turn it into a carboxylic acid with a sodium chloride biproduct. Is this correct?

Also are my other answers okay, or should I look over them again?

Thank You

[Yggdrasil]

All of them look good except for this one:

3. methyl 3-methylbutanoate + sodium hydroxide=???

To form an acyl anhydride you need to treat a deprotonated carboxylic acid with an acyl chloride.  Here you have neither a carboxylic acid nor an acyl chloride; methyl 3-methylbutanoate is an ester.  Treating an ester with (aqueous) base results in a saponification reaction.  The ester is hydrolyzed to produce methanol and sodium 3-methylbutanoate (which becomes 3-methylbutanoic acid after acid workup).

[jena]

Thanks you guys

Especially with the last reply

To form an acyl anhydride you need to treat a deprotonated carboxylic acid with an acyl chloride.  Here you have neither a carboxylic acid nor an acyl chloride; methyl 3-methylbutanoate is an ester.  Treating an ester with (aqueous) base results in a saponification reaction.  The ester is hydrolyzed to produce methanol and sodium 3-methylbutanoate (which becomes 3-methylbutanoic acid after acid workup).

I ended up finding it the book as well  


I got some more questions, if you don't mind looking over them

My questions are:

1. 3-methylbutanoic acid + SOCl₂=  

2. 3-methylbutanoic acid + DCc, methanamine=

3. 3-methylbutanoic acid + heat=

4. 3-methylbutanoic acid +methanol acid catalysis=???

5. diethyl heptanediaote + sodium ethoxide + bromoethane + hydrolysi + heat=???

My Answers:

1. 3-methylbutanoyl chloride, because a carboxylic acid with a SOCl₂ and pyridine catalyst make a Acyl halide.

2. N,3-dimethylbutanamide, because carboxylic acid with amine, followed by DCC will results in a amide that's either primary, secondary, or tertiary.

3. 3-methyl butananoic anhydride, because carboxylic acid with heat and assuming an acid cataylst will result in an anhydride.

4. methyl 3-methylbutanoate, because carboxylic acid with an alcohol followed with an acid catalyst will result in an ester alkyl alkanoate.

5. cyclohexanone , with this one I know that at least I'm going to form a cyclohexanone, but I'm not sure if I keep an ethyl group attached to it.

Are these correct???

Thank You

[movies]

For number 5, look into the Dieckmann condensation and think about the intermediates you have along the way to the product.  How could they react with the other reagents you have?

By the way, I have run an almost identical reaction to this in my own research.  It's a very good reaction!

[jena]

Hi,

Yep , question 5 is cyclohexanone, and I do remove the little ethyl attachement.

Thank You