Rearrangements Beckmann-type

Reaction of nitromalon-bis-A -methylanilide (105) with sulfuric acid gives A -methylisatin- -oxime (107) and not 4-methylquinoxalin-3-one 1-oxide (108) as originally suggested. This transformation may involve a Beckmann-type rearrangement of the protonated aci-nitro compound (106) prior to dehydrative ring closure. ... 

KOSiMe3 by a Beckmann-type rearrangement [39], and from glutamic acid derivatives by intramolecular acylation [40]. 

Eshghi, H., Gordi, Z. An Easy Method for the Generation of Amides from Ketones by a Beckmann Type Rearrangement Mediated by Microwave. Synth. Commun. 2003, 33, 2971-2978. 

Perhaps the commonest ring expansion method of azocine synthesis is by Beckmann or Beckmann-type rearrangements of cycloheptanone... 

The major ring expansion route to the dibenzazocines is via a Beckmann or Beckmann-type rearrangement of the oxime. Lactams 160313 and 161314 were prepared by ring expansion of the corresponding dibenzosuberones. Other dibenz[b,/]azocines have been similarly made.315 320 The fully unsaturated dibenzazocine 162 has also been prepared from the corresponding lactam in a manner similar to that used for 118 (Scheme 3).260... 

There are regularly publications concerning the transformation of bomane derivatives [particularly camphor (40) oxime] to campholenyl derivatives, but there is no particular interest attached to them as syntheses of natural products. Nevertheless, we mention work on the Beckmann-type rearrangements of camphor oxime,and a route to campholenic alcohol (352) from the hydroxycamphene 353. "Y-Campholenol (354) has been identified in Tanacetum... 

Nitrogen replaces carbon on the P atom in Beckmann-type rearrangements [11] (13.264) and in Lossens-type transformations [12] (13.265). 

Scheme 36 Benzimidazole 130 formation via Beckmann-type rearrangement...

It has also been demonstrated that o-hydroxyaryl-ketimines 127 tmdergo an iodine(in)-mediated Beckmann-type rearrangement to produce benzoxazoles 128 as outlined in Scheme 35 [29]. 

The authors assumed that under the reaction conditions, the adducts 463 were formed in the 1,3-cycloaddition, but then undergo a Beckmann-type rearrangement... 

Martinez-Aseneio A, Yus M, Ramon DJ (2012) Copper(II) acetate-catalyzed one-pot conversion of aldehydes into primary amides through a Beckmann-type rearrangement. Tetrahedron 68(21) 3948-3951... 

Liu and co-workers developed a AgN02-mediated direct transformation of 2-methyl quinoxalines to related nitriles [124]. The reaction could involve NO radical and aldoxime intermediates. In the presence of K2S2O8, the nitrile would be generated by the Beckmann type rearrangement (cf. Wang s work). Interestingly, nitration of quinoxalines could occur when tertiary benzylic C-H bond presents in it (Scheme 4.27). 

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