Hoch-Campbell reaction

The third variation of the Hoch-Campbell reaction is the replacement of the... 

Grignard reagents with LiAlUt. Evidently, the R would be hydride in this case. The mechanism is strikingly similar to that of the Hoch-Campbell reaction except the azirine is attacked by hydride rather than the Grignard reagent. 

Oxime 26 was prepared from 5,ll-dihydro-dibenzo[a,d]cyclohepten-10-one. The Hoch-Campbell reaction of 26 with 3-dimethylaminopropylmagnesium bromide produced aziridine 27 in 46% yield after acidic workup. Extension of the Hoch-Campbell reaction to steroids has also been reported. Thus, treatment of 3(3-hydroxy-5-pregnen-20-one oxime (28) with methylmagnesium iodide furnished a mixture of diastereomers, 20ot/20P,21-imino-20-methyl-5-pregnen-3P-ol (29) in a 50% combined yield and a 3 1 ratio. On the other hand, homo-adamantan-4-one oxime (30) was transformed to homo-adamantano[4,5-b]-2 -ethylaziridine (31) in 76% yield upon the action of... 

Secondary aziridines bearing a trifluoromethyl group were prepared via the Hoch-Campbell reaction of Grignard reagents and oximes bearing a trifluoromethyl... 

When both a-positions of the oxime possess active hydrogen, the regiochemistry of the Hoch-Campbell reaction prefers the side with more available hydrogens— indicating the process is kinetically controlled. In case of oxime 36, azirine 37 was not formed. Instead, azirine 38 was obtained exclusively. Addition of the third equivalent of the Grignard reagent delivered aziridine 39 as a mixture of two diastereomers. 

The Hoch-Campbell reaction of a-hydroxy ketoximes do not alter the course of the reaction although deprotonation probably took place concurrently for both the alcohol and the oxime. Treatment of oxime 40 afforded aziridine 42 in 30%, presumably via the intermediacy of azirine 41. a-Keto ketoximes would behave similarly to the a-hydroxy ketoximes in the Hoch-Campbell reaction after addition of the first equivalent of the Grignard reagent to the ketone. Therefore, the reaction between a-keto ketoxime 43 and phenylmagnesium bromide gave aziridine 45 in 41% yield, presumably via the intermediacy of azirine 44. 

Synthetic methods which utilize the addition of nucleophiles to a-halo oximes and similar compounds (the Hoch-Campbell reaction) have been reviewed. ... 

The Neber rearrangement650-653 is a method for preparing a-amino ketones by base-catalyzed intramolecular rearrangement of ketoxime O-sulfonates. The intermediate azirine,654-656 which can be isolated, can also lead to aziridine derivatives when the base is lithium aluminum hydride657 or a Grignard reagent (the Hoch-Campbell reaction)658,659 (Eq. 190). 

Other references related to the Hoch-Campbell reaction are cited in the literature. 

In essence, the stage of azirine formation resembles the azirine synthesis from oximes or their ethers by the Hoch-Campbell reaction [344—348]. 

The discussion of the mechanism of pyrrole synthesis from ketoximes and acetylene should also account for a possibility of azirine intermediate (or its open-chain forms, zwitterion and vinyl nitrene) participation in the reaction, since ketoximes are known to undergo 1,3-dehydration under the influence of the strong bases to produce azirines (the Hoch-Campbell reaction) (Scheme 1.207) [344-348]. 

This reaction is known as the Hoch-Campbell aziridine synthesis, which entails treatment of ketoximes with excess Grignard reagents and subsequent hydrolysis of the organometallic complex to produce aziridines. 

Graham reaction—additive oxidation Hoch-Campbell aziridine synthesis Payne rearrangement Wenker synthesis Aziridine synthesis... 

Hinsberg Synthesis of Thiophene Derivatives Hiyama (see Nozaki-Hiyama Coupling Reaction) Hoch-Campbell Aziridine Synthesis Hoesch (see Houben-Hoesch Reaction)... 

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