Synthesis of Allyl Hexanoate: Challenges and Strategies

[albinoscout14]

I am attempting to synthesize some allyl hexanoate and I am having a little bit of a hard time figuring out the procudure to go about it. I am going to start with n-hexanol, and using Na2Cr2O7 and H2SO4, create hexanoic acid through oxidation. Then I was going to run an ether synthesis starting by reacting allyl alcohol with TsCl and pyridine, and then adding to that the hexanoic acid. I have a procedure from a previous lab that I did that is similar for the oxidation, but instead of using the Cr VI reagent we used NaOCl (bleach), but I am not sure how well it will help me. On the other hand I am at a loss for where to start in the ether synthesis.

 

[chemisttree]

You are trying to make an ester, not an ether.

Why not use SOCl2 on the hexanoic acid?

 

[gravenewworld]

yes make the acid chloride. from personal experience, pyridine is a pain in the neck to get rid of.

 

[chemisttree]

yes make the acid chloride. from personal experience, pyridine is a pain in the neck to get rid of.

Have you ever tried codistilling the last vestiges of py (bp=115C) using heptane (bp=98C) in the rotovap? It works great for small amounts and if the product doesn't smear out on the surface of the vessel (soluble in heptane). I use it to make my clean NMR sample and for the elemental analysis work.

 

[gravenewworld]

Have you ever tried codistilling the last vestiges of py (bp=115C) using heptane (bp=98C) in the rotovap? It works great for small amounts and if the product doesn't smear out on the surface of the vessel (soluble in heptane). I use it to make my clean NMR sample and for the elemental analysis work.

Hmmm never tried that. The only thing I tried was taking up my crude product in some 1N aq. HCl in order to make the HCl salt of the pyridine which should be water soluble. I then extracted the aq. with ethyl acetate to get my product out. It seemed to work. If the product were acid sensitive or had some basic moities then it probably would have been more of a pain of the neck since I wouldn't have been able to use the acid extraction. i suppose also I could have used an ion exchange column really quick to suck up a lot of the pyridine.