[xir]

Hello to all

i am a third year undergrad student from the university of Manchester, i am currently doing a Mchem project on palladium complex catalysts.

One of the areas we have decided to work on is to create 2 cyclohexene-1-ol from 2-cyclohexene-1-one, so we can create varied complex structures. You may ask why we don't just buy it, well it will cost us £77 for just 5 grams of material which is no where near enough for what we want and nowhere inside our budget.

We have had some issues with this reaction reducing the alkene bond as well as the carbonyl.

So far we have tried
aluminium oxide with water and NaBh₄ with some limited success.
NaBh₄ with Me-OH and aceta nitrile (with limited success in combination with above)
And a cerium reaction that utterly failed.

I was wondering if anyone had any experience with these types of reductions or had any knowledge of research papers i could WOK into.

Any and all help is most appreciated.

[Dan]

How about 9-BBN?

Here's a paper:

Journal of Organic Chemistry  (1977),  42(7),  1197-1201

[xir]

Thank you ever so much, im amazed at the speed of your response. it does indeed show what i am looking for, im now passing on the method to my supervisor (with due credit to yourself and the forums).

I hope you don't mind me asking but how did you know of this article, was it just from memory or did you use a specific method to find it? if so could you tell me more about it?

[Dan]

No problem. I didn't pull that one from memory, I immediately thought of the Ce(III) method, but you said that failed so I used ISI web of science, go here:

http://portal.isiknowledge.com/portal.cgi

and select "web of science" from the drop down "products and features" menu found in the middle of the green bar at the top of the page (and press "go").

Then select the "general search" button.

My search was as follows:

In the "topic" field I searched for this phrase: selective reduction conjugated ketone*

I also checked the "title only" box.

note the asterisk, this is so that "ketone" or "ketones" will return a result. Result 7 was that paper I gave you the ref for.

On the general search page there is a link to general search tutorials. I'd suggest checking them out if you're not familiar with web of science because it's very easy to get nothing useful from a search...

SciFinder Scholar is much much better. I know for a fact that at Manchester Uni you have access to it (a licence for 6 or 7 simultaneous sessions last I heard) so that is definately worth looking into.

I just had a look in March's and he also suggests BH₃-SMe₂ [J. Org. Chem. 1978, 43, 1829] In this paper they report the reduction of cylohexenone to cyclohexenol in 2 mins with 94% yield. Not too shabby! It is also also much cheaper than 9-BBN and you only need to use 0.3 molar equivalents. So that looks like a winner.

[Rico]

Hey xir.

I actually have some experience in reducing this kind of system. Once i reduced a 2-cyclohexenone having an alkyl chain (with a tosylate on it) in the 3-position. I did the reduction with DIBAL (diisobutylaluminumhydride) and the reduction worked quite good. Afterwards i acetylated the alcohol group with acetic anhydride. A word of caution, these allylic alcohols are unstable towards acid and they can eliminate water giving diene products. Even the acetylated version can eliminate acetic acid also giving a diene.

Rico