FORSTER Diazo synthesis

FORSTER Diazo Synthesis Formation ol diazo denvatives from oximes... 

FORSTER Diazo Synthesis Formation of diazo derivatives from oximes (see 1st edition). 

The present procedure for the synthesis of an a-diazo ketone is a modification of the Forster reaction,which has been recently exploited by numerous workers.The synthesis is generally applicable to cyclic ketones, is convenient, and offers moderate yields (60-70%) of pure a-diazo ketones. 

Forster s method was ignored for many decades, until it was realized that it is useful for the synthesis of a-diazo ketones (Horner et al., 1958, 1959 Cava et al., 1958 Jung et al., 1985). 

The application of the Forster reaction to the synthesis of a-diazo ketones is particularly important for derivatives of indanone and steroidal ketones with a methylene group in the a-position to the carbonyl function. The reaction allows functionalization of the a-methylene group. Examples include the synthesis of 2-diazo-3,3-diphenyl-indan-l-one (2-42 Cava et al., 1958) and 16-diazo-3)ff-hydro-xy-androst-5-en-17-one (2-43, Muller et al., 1962 Wheeler and Meinwald, 1988). 

This reaction was initially reported by Forster in 1915. It is the synthesis of diazoketones, especially for the cyclic diazoketones from a-keto oximes by the reaction with chloramines. Therefore, it is known as the Forster reaction. Although two mechanisms have been proposed for this reaction,experimental evidence favors the one involving the attack of NH2CI by the lone-pair electrons of the oxime nitrogen. " This reaction has been modified via the generation of chloramine in situ, which is used in the preparation of 2-diazo-1 -indanones. ... 

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See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

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