申请人:Pfizer Inc.
公开号:US04126624A1
公开(公告)日:1978-11-21
Gamma-pyrones are prepared by contacting a 3-halo-furfuryl alcohol or a 3-alkoxy-furfuryl alcohol with one equivalent of a halogen, peracid or peroxide oxidant and then heating until hydrolysis of the formed 4-substituted-dihydropyran intermediate is substantially complete. Maltol (2-methyl-3-hydroxy-4H-pyran-4-one) is prepared by this process from 2(1-hydroxyethyl)-3-alkoxy furans or 2(1-hydroxyethyl)-3-halo-furans. Gamma-pyrones are also prepared by contacting the corresponding 3-substituted-2,5-dialkoxy-furfuryl alcohols with acid until conversion to the gamma-pyrones is substantially complete.
Gamma-吡喃酮是通过将3-卤代呋喃基醇或3-烷氧基呋喃基醇与等量的卤素、过氧酸或过氧化物氧化剂接触,然后加热直至形成的4-取代二氢吡喃中间体的水解基本完成而制备的。从2(1-羟基乙基)-3-烷氧基呋喃或2(1-羟基乙基)-3-卤代呋喃中通过这个过程制备了麦芽酮(2-甲基-3-羟基-4H-吡喃-4-酮)。通过将相应的3-取代-2,5-二烷氧基呋喃基醇与酸接触直至转化为Gamma-吡喃酮基本完成,也可以制备Gamma-吡喃酮。