(Hive Addict)
09-24-03 00:03
No 460620
(Rated as: good read)
Mg(OMe)2 - you may remember that one from Post 212002 (Rhodium: "Easy nitroethane in quantitative yield", Methods Discourse) or Post 290438 (Lilienthal: "2-hydroxy-5-MeO-BA: The easy way", Chemistry Discourse). I haven't seen this prep. here before, though I guess some of you may bee familiar with it.
Mg alkoxides are prepared by heating 0.1mol of Mg powder, 0.002mol of I2,
0.2 mol of alcohol at 60°C until the iodine color disappeares. Another 0.4 mol
of alcohol are then added and the mixture is refluxed until all Mg powder
is digested.
Now, that last sentance isn't exactly what the article said since it originally deals with the synthesis of benzyl/allyl alkylethers from Mg alkoxide and benzyl/allylhalide. But you get the picture, Liebig could have done it. In the Ref the amount of alc added after the soln clears from iodine varies on what ether is the target. they used 0.6 mol alc in the example with the least additional alc, but I guess 0.4 mol is also OK, since more just dilutes the product further. Things should clear up after some experimentation.
Ref: Lin, Ji-Mao; Li, Hui-Hui; Zhou, Ai-Min; TELEAY; Tetrahedron Lett.; EN; 37; 29; 1996; 5159-5160
--psyloxy--
