Carroll Robert J, Leisch Hannes, Rochon Lena, Hudlicky Tomas, Cox D Phillip
Department of Chemistry and Centre for Biotechnology, Brock University, 500 Glenridge Avenue, St. Catharines, ON, Canada, L2S 3A1.
J Org Chem. 2009 Jan 16;74(2):747-52. doi: 10.1021/jo802454v.
The ethylene glycol ketal of neopinone was prepared in a one-pot procedure by the reaction of thebaine with ethylene glyocol in the presence of p-toluenesulfonic acid. The ketal is also an intermediate in the conversion of thebaine to hydrocodone with ethylene glycol and Pd(OAc)(2), followed by hydrogenation. Additionally, a one-pot procedure for the conversion of thebaine to hydrocodone was achieved by employing palladium catalysis in aqueous medium. Palladium serves a dual purpose in this transformation, first for the activation of the dienol ether of thebaine and second as a hydrogenation catalyst. This procedure was found to be comparable to the two-step protocol which employs diimide reduction of thebaine followed by acid-catalyzed hydrolysis of the resulting 8,14-dihydrothebaine to hydrocodone. Experimental and spectral data are provided for all compounds.
新匹诺酮的乙二醇缩酮是通过在对甲苯磺酸存在下，将蒂巴因与乙二醇反应，采用一锅法制备的。该缩酮也是在将蒂巴因用乙二醇和醋酸钯（II）转化为氢可酮，随后进行氢化反应过程中的中间体。此外，通过在水性介质中采用钯催化，实现了将蒂巴因一锅法转化为氢可酮。钯在该转化过程中具有双重作用，首先用于活化蒂巴因的二烯醇醚，其次作为氢化催化剂。发现该方法与两步法相当，两步法是先对蒂巴因进行二亚胺还原，然后将所得的8,14 - 二氢蒂巴因进行酸催化水解得到氢可酮。提供了所有化合物的实验和光谱数据。
