Sciencemadness Discussion Board


ChemichaelRXN - 13-12-2020 at 06:59


Has anyone ever performed a Grignard reaction where you are reacting two halogen groups with two moles of the ketone? Using the compound 1,4-dibromobutane and acetone or even MEK.

The compound Id produce would be 2,2,7,7-tetramethyloxepane, somewhat similar to 2,2,5,5-tetramethyltetrahydrofuran (TMTHF), naturally found in the mycelium of Tuber borchii (truffles). I’d try to use H-Beta-zeolite for the cyclization of 2,7-dimethyloctane-2,7-diol.

I think it would be a fun couple step reaction to do, but I want to know what to expect in the Grignard. Think it would spontaneously combust?

F8157E2A-5E7B-4654-BF92-9864C346013E.jpeg - 23kB

Pumukli - 13-12-2020 at 08:06

Ask Henry Gilman! :-)

He studied Grignard reactions extensively and compiled a good article on them in "Organic Reactions" in the 1940-ies. He even mentioned the reactions of alpha,omega-dihaloalkanes in that article... As far as I remember his verdict was this route was OK and went more or less according to theory.

So I encourage you to pursue this route, your target compound seems (smells?) gorgeous! :-)

ChemichaelRXN - 13-12-2020 at 09:43

Yea, it might just work. I recall hearing anything less than the 1,4-dibromobutane would just break apart. I will have to wait until the summer before I can do this. I dont handle anything flammable with a low boiling point like THF or ether indoors in the fume hood and would do this outside. I have the 1,4-dibromobutane and pretty much everything else luckily. Apparently that dihaloalkane is bad for the eyes, which makes me a little lazy about handling it.

Yea, the odour must be reminiscent of the 2,2,5,5-tetramethylTHF. I would definitely document the product well if I achieve success with the final cyclization.