Beckmann rearrangement cyclisation

R. E. Gawley, The Beckmann Reactions Rearrangements, Elimination- Additions, Fragmentations, and Rearrangement-Cyclisations, Org. React. (N.Y.) 1987, 35, 1. 

Tandem Beckmann Rearrangement and Allyl Silane Cyclisation... 

Matsumoto and co-workers succeeded in obtaining the desired cyclisation of the Turner intermediate (65 R = H or OMe) into (66). The carbonyl group was removed from (66) by the dithioketal procedure and the product converted to the ketone (67). Nitrosation of the ketone followed by Beckmann rearrange-... 

A device that has been frequently used to produce an ortto-acylamino-phenol synthon is to carry out a Beckmann rearrangement on an ort/to-hydroxyaryl ketone, the Beckmann intermediate cyclising in situ, as illustrated below. ... 

The -lactam-ester (468), obtained by Beckmann rearrangement of the oxime (467), has been reduced and cyclised to give the /5-lactam (469). ... 

Further work has been described on the formation of aza-steroids by the cyclisation of methine bases obtained by Hofmann degradation of perhydro-azepines. Thus, Beckmann rearrangement of the cholestan-3-, -4-, -6-, and -7-one oximes followed by lithium aluminium hydride reduction afforded the 4- and... 

A device which has been frequently used to produce a starting material with just one acyl group in place is to carry out a Beckmann rearrangement on an ortho-hydroxyaryl ketone, the Beckmann product cyclising in situ when the conditions are acidic a modern version of this is illustrated below." " An excellent route to mono-acylated precursors utilises mixed anhydrides.A very mild method for the dehydrative ring closure of or /io-hydroxyarylamino amides, employed in solid-supported benzoxazole syntheses, utilises typical Mitsunobu conditions - triphenyl-phosphine and diethyl azodicarboxylate." ... 

Treatment of the oxime 6>-mesylate 13 with DIBAL resulted in the formation of the tricyclic benz-3-azepine 14 in a stereoselective tandem Beckmann rearrangement / allylsilane cyclisation <97SL632>. Treatment of ketoximes with divinylketone or its equivalents affords mixtures of the bridged heterocycles 15 and 16 <97TL6099>. In most cases formation of the 7-membered ring predominates, particularly in polar solvents. 

Because of their negligible vapor pressure, thermal stability and easy recyclability, neutral ILs have been referred to as environmentally benign solvents. These ILs have been employed as excellent and recyclable medium for a wide array of reactions e.g., Heck reaction [Park Alper, 2003], Bischler-Napierlaski cyclisation [fudeh et al, 2002], Beckmann rearrangement [Ren et al., 2001], addition of thiols to unsaturated ketones [Yadav et al., 2003], 1-proline catalysed aldol reaction [Loh et al., 2002], and Pechmann condensation of phenols and ethyl acetoacetate (EAA) catalyzed by POCI3 in [bmim]PF6 and [bmim]BF4 ILs [Potdar et al., 2005]. Other examples where ILs have been used as a reaction media include, but not limited to, Diels-Alder reactions [Reinhardt, 2009 Doherty, 2004 Song, 2001], Friedel-Crafts alkylation and acylation reactions [Xiao, 2006 Xiao Malhotra, 2005 ... 

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