Deazaflavin analogues

IR spectroscopy has also been used in structural problems in 2- and 3-hydroxypyrido[3,4-f ]pyrazines (63JCS5156), in 8-oxopyrido[2,3-f ]pyrazine-7-acids (73MI21501) and in the pyrido[3,4-f ]quinoxaline field (74JCS(P1)1965). IR spectra were recommended for the distinction of isomeric products in the Isay reaction (Section 2.15.15.6.1) (71TH21500) UV spectra were not satisfactory. The Raman spectra of a number of 1- and 3-deazaflavin analogues have been recorded and discussed (80BBA(623)77). 

As mentioned earlier (page 405), 5-deazaflavin analogues are more susceptible to nucleophilic attack which typically occurs at position 5 to yield 1,5-dihydro adducts. In this respect, the formation of a 4a,5-epoxy-5-deazaflavin derivative by the reaction of 5-deaza-isoalloxazine with H2O2, tert-butyl hydroperoxide, or m-chloroperbenzoic acid has been reported recently (294). 

The values have been measured by a rapid reaction method, as have those for a series of 5-hydroxy and 8-hydroxy analogues of oxine (e.g. 54JCS505, 66JCS(B)436), and for other deazaflavins and pyridopyrazines (78B1942, 68JOC2393). 

Reduction of the 5-deaza-analogue of FMN under a catalysis of NADH /FMN oxidoreductase was investigated (Fisher and Walsh 1974) and direct transfer of the pro-R hydrogen of NADH onto the 5 position of 5-deazaflavin was observed (Scheme 28). 

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