Reactions of amines. XVIII. Oxidative rearrangement of amides with lead tetraacetate

Abstract

References and Notes(1) For previous paper in this series see . K. Meilahn and . E. Munk, J.

Organic Carbamates in Drug Design and Medicinal Chemistry

“… 46 Much effort has been devoted to the development of modified reagents to optimize the Hofmann rearrangement since the classical method for this transformation, involving the use of an alkaline solution of bromine, is unsatisfactory and unreliable. 35 A variety of oxidants and bases have been proposed as modified agents, e.g., iodine(III) reagents such as PhI(OAc) 2 , 47 MeOBr, 48 NBS-CH 3 ONa, 49 NBS-KOH, 46 lead tetraacetate, 50 and benzyltrimethylammonium tribromide. 51 These modified methods, however, require more than 1 equiv or an excess amount of the oxidizing reagent, which is not very convenient.…”

Unusually large reactivity differences in the transformation of cyclopropane lactones to 1‐aminocyclopropane‐1‐phosphonic acids and their carboxylic acid analogues

“…To obtain the phosphonic acid analogue 11 (ACP) of the aminocyclopropane carboxylic acid (ACC) the alcoholic OH group in 7 was protected by formation of a dimethyl tert-butylsilyl ether, and then a Hofmann rearrangement was performed by the action of lead tetraacetate in the presence of tert-butanol [12], resulting in the formation of the tert-butoxycarbonyl (BOC) protected aminocyclopropane phosphonate 9. For the removal of the BOC group from 9, the BF 3 etherate reagent proved to be the best [13], removing, at the same time, the silyloxy group from the alcoholic moiety to give 10 (Scheme 6).…”

Synthesis of d-camphor based γ-amino acid (1S,3R)-3-amino-2,2,3-trimethylcyclopentane carboxylic acid

“…Baumgarten et al 6 have synthesized 5 from D-camphoric acid 6 by preparing the c-amido ester 7 and conducted the Hofmann rearrangement with lead tetraacetate and tin tetrachloride (Scheme 1). The resultant carbamate 8 was then hydrolyzed to afford 5.…”