Search results
Results from the WOW.Com Content Network
The Hofmann rearrangement (Hofmann degradation) is the organic reaction of a primary amide to a primary amine with one less carbon atom. [ 1 ] [ 2 ] [ 3 ] The reaction involves oxidation of the nitrogen followed by rearrangement of the carbonyl and nitrogen to give an isocyanate intermediate.
Deprotonation of the Seyferth–Gilbert reagent A gives an anion B, which reacts with the ketone to form the oxaphosphetane D. Elimination of dimethylphosphate E gives the vinyl diazo-intermediate Fa and Fb. The generation of nitrogen gas gives a vinyl carbene G, which via a 1,2-migration forms the desired alkyne H.
The Cope elimination is very similar to the Hofmann elimination in principle, but occurs under milder conditions. It also favors the formation of the Hofmann product, and for the same reasons. [3] An example of a Hofmann elimination (not involving a contrast between a Zaitsev product and a Hofmann product) is the synthesis of trans-cyclooctene. [4]
The resulting sodium salt of phthalamic acid is decarbonylated via a Hofmann rearrangement of the amide group, induced by hypochlorite: [15] C 6 H 4 (C(O)NH 2)CO 2 Na + HOCl → C 6 H 4 NH 2 CO 2 H + NaCl + CO 2. A related method involves treating phthalimide with sodium hypobromite in aqueous sodium hydroxide, followed by neutralization. [16]
This organic reaction is closely related to the Hofmann elimination, but the base is a part of the leaving group. Sulfoxides can undergo an essentially identical reaction to produce sulfenic acids, which is important in the antioxidant chemistry of garlic and other alliums. Selenoxides likewise undergo selenoxide eliminations.
A U.K. woman had her breast cancer detected through AI after a routine mammogram came back as normal. Experts Drs. Nicole Saphier and Harvey Castro discuss the power of AI in cancer care.
The Tar Heels program is certain to experience a complete overhaul in the next several months. During his interview with McAfee, Belichick made it quite clear: He’d bring an NFL mentality and ...
Lauren Conrad/Instagram. Trey Phillips, Lauren Conrad and Dieter Schmitz at their 20th high school reunion; Laguna Beach High School’s Class of 2004 members in photos taken on Nov. 30, 2024