08-16-01 17:31
No 205283
Hey guys,
I wondered if you could clear something up for me. I keep hearing the use of psudoephedrine as a precursor in the Birch rxn. I thought reduction of a benzyl alchol via "Birch" yields 99.8 percent straight conversion from one enantiomer of ephedrine to the corresponding+/- enantiomer of N-methyl amphetamine, unracemized (JACS reduction of benzy;). If this is true, then wouldn't SWIM get active product if he were to start with the + ephedrine salt, instead of the pseudo?
I'll sleep when I'm dead
(Stoni's sexual toy)
08-16-01 17:49
No 205291
I'm kinda confused about the chiralities of ephedrines and pseudoephedrines right now. But I think the reason is the following: ephedrine and pseudoephedrine have TWO chirality centers, the benzylic position and the carbon to which the amine functionality is connected. When doing a Birch you reduce the benzylic OH, and this chirality center disappears, and only one is left.
(Hive Bee)
08-17-01 01:29
No 205382
yep, pseudoephedrine and ephedrine differ on the -OH carbon. both should give the good stuff.
Man was not born to work.
(Professional Student)
08-17-01 09:11
No 205420
wouldn't SWIM get active product if he were to start with the + ephedrine salt, instead of the pseudo? ..I believe you will be needing (-)ephedrine.
Back to the Primitive
(Hive Bee)
08-17-01 12:17
No 205460
This is in the search engine. I have posted the correct answer several times.
d-psuedoephedrine yeilds d-meth
l-ephedrine yields d-meth
l-psuedo yeilds l-meth
d-ephedrine yields l-meth