kclo4 - 18-6-2007 at 23:11
Hello people 
its been a long time since i have been on this forum, sad really
but anyways i have came up with a problem that i can't figure out by myself
alright there is a furan "molecule" attached to more or less, a benzene ring and then benzene ring is attached to 3 others,
so now my question is how can i take off this furan ring with out messing up or screwing with the other rings?
the rings have other things on them but its completely ok if they are destroyed and so im not going to take the time explaining them
so who here can help me take off the furan ring?
if it helps and im sure it does the furan ring is attached to another carbon, 2 right of the oxygen in the furan ring
so yes.. please help :]
Sauron - 19-6-2007 at 07:02
Kindly supply a structural drawing so we can (hopefully) comment intelligently.
kclo4 - 19-6-2007 at 11:07
there ya go 
Sergei_Eisenstein - 19-6-2007 at 11:53
I don't see anything in this drawing that more or less resembles a benzene ring, so basically I'm not confident you and me see the same furan ring.
But the one I see is difficult to remove chemically, unless you are allowed to ruin the rest of the molecule. I'd be interested to know why you want
to do this kind of reaction, especially because financial resources are invested in finding suitable synthetic procedures to incorporate the furan
ring.
hinz - 19-6-2007 at 11:57
Why do you want to destroy that beautiful molecule only to get furane. I mean you have probably extrated these salvinorins from Salvia divinorum and
you only want to destroy them to get furane. Some people would give you alot of furan in trade for this stuff. It's a drug, but not a bad one I think,
so I wouldn't destroy it to get furan.
Futhermore you can't really get the furan out of it, C-C bonds are mostly hard to break, and only because furan is in a stuctural drawing, it's not
always possible to get it out of it, there are a lot of examples of it, like benzoic acid to benzene.
kclo4 - 19-6-2007 at 12:31
No and no
i want the rest of the molecule, with out the furan i don't care at all about the furane junk
i just want the 3 rings that are together
not_important - 19-6-2007 at 15:31
I remember reading about organometalllics that might tie up with the furan ring and activate it enough that it could be attacked and opened
after several steps. But that's going to leave a CO2H hanging onto ring 3, and it's going to be difficult to remove.
I don't think any of these proposed starting materials are present in much quantity, combined with the likely loses in reactions it looks to be a
rather poor route to the underlying structure you want. I suspect you'd do much better starting with naphthalene, putting on the foundations of ring
3, and reducing the aromatic rings. Well, except for carbons 19 and 20, which would a bit more cleverness.
Diels-Alder is another possibility, although intermediates might be a problem to get to.
But if you insist on starting with the materials you indicated, I suspect that you'll have to find an enzyme based route. Time to start hunting down
the proper bacterial strains...
kclo4 - 19-6-2007 at 22:37
hmmm i don't think naphthalene could be made into the same chemical... pretty sure of it
but thank you for mentioning the organometallics
and its ok to leave a CO2H behind, it might actually be good
Sauron - 20-6-2007 at 00:07
As someone else pointed out, not a benzene ring in sight. Those are a cyclohexene fused to a cycloxexane and a lactone built onto that, plenty of
chiral centers present.
Some sort of terpene I'd guess. I would think you'd have to open up that lactone to have any shot at cleaving off the furan at all. What would be
left would be some sort of decalin or tetralin derivative, and you'd have to try to rebuild the lactone ring. Sounds not at all trivial.
Nicodem - 20-6-2007 at 10:50
There is no way to oxidize the furan-3-yl moiety without first protecting the double bond at the octahydronaphthalene moiety. And even then you are
still left with oxidazible R2 in salviasplendin A and R1 in splenolide A. Also, the C(12) would likely get oxidazed all the way to COOH, so that you
would not be able to rebuild the lactone ring.
So, which compound of the five depicted you want to destroy?
kclo4 - 20-6-2007 at 13:10
alright, so instead of destroying this molecule, to make the just 3 ringed thingy, how can i make the 3 rings?