dormouse
(Member) 04-19-00 09:45 No 122814 |
Birch Mechanism -bbman | Bookmark | ||||||
the Hive BB Serious Chemistry Forum Birch Mechanism profile | register | preferences | faq | search next newest topic | next oldest topic Author Topic: Birch Mechanism bbman Junior Member posted 12-14-1999 12:26 PM ---------------------------------------- I'm trying to understand the mechanism of the Brich reduction of PSE to Meth. I found a regerence which suggests that the mechanism procedds as an elimination with a double bond formed between the ring and the alpha carbon, followed by hydrogenation across the double bond. In this reaction Ammonium CHloride is added to quench the reaction. My question is if this is the mechanism, can one get a di-phenyl compound formed due to the free electron in the para position to the alpha carbon? Here is a description of the mechanism: " The dissolved lithium metal gives up an electron to the ring and forms a radical anion. The hydroxyl group is eliminated, forming a double bond between the ring and the alpha carbon. A second atopm of Lihium gives up an electron to the radical, and the resulting carbanion is protonated by the ammonium chloride. Through keto-enol tauterism, methamphetamine is formed as the more stable species". ------------------ |
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