It's been a while since I took Organic Chem.
This is what I think, but you should definitely look it up.
1. You would have to get the -OH on the cyclohexanol to =O with the CO2 and EtOH, that way you create a partial +ve charge on the C that's attached to the O.
ie. (C5H10)-C-OH -------> (C5H10)-C=O
ring | ring |
H H
Substrate A Product B
2. Product B will undergo a process where you will get a double bond between 2 C, where 1 of the C will have a +ve charge and the O will have a full negative charge (-v) -----Can't remember the term for it. I think it's something like enolization(?) sorry can't remember.
This enolized(?) version of Product B will interact with product B to get the two cyclohexanes joined together each having a single OH on it.
3. You would then reduce the 2 OHs by using a reducing agent.
I think that's how you do it. Like I said, you better check it up in the org. chem. text. because I'm doing this problem from the top of my head. I hope it helps you on the right track.
AE
