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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: baum0372 on July 26, 2011, 01:36:09 PM

Title: Zinc Dust Ammonium Chloride Reaction
Post by: baum0372 on July 26, 2011, 01:36:09 PM

I am looking at a reaction where Zinc Dust and ammonium chloride in water and ether splits a hemiketal into a ketone and terminal alkene.  I am very unfamiliar with metals and so I don't know even where to start to try and figure out the mechanism.  I do know that the hydroxyl group turns into the ketone and that there looks to be the loss of water.

Any help with even how zinc dust and ammonium chloride react would be helpful as well.  Thanks!

Title: Re: Zinc Dust Ammonium Chloride Reaction
Post by: opsomath on July 26, 2011, 03:25:37 PM

This combination is a moderately powerful reducing agent. I have used it to change NO2 groups to NH2 with great success.

I think acid (NH4Cl) will immediately cleave your hemiacetal to a ketone and alcohol. That gives the halohydrin on the loose chain. Then I think it's just a standard reaction like so:

http://clem.mscd.edu/~wiederm/oc1chp/oc1chptopic1/page3.htm

Title: Re: Zinc Dust Ammonium Chloride Reaction
Post by: orgopete on July 26, 2011, 03:30:41 PM

You have not shown Zn in your scheme. What do you think the (missing) products of that reaction might be? I would start there.