Alkyl nitronates nitroso acetal functionalization

Aside from the relatively trivial conversions of nitronates to the corresponding oxime and carbonyl compounds (10,11), the chemistry of nitronates remained relatively unexplored for much of the early 1900s. However, in 1964, Tartakovskii et al. (12) demonstrated that alkyl nitronate esters were competent partners in the newly discovered class of dipolar cycloadditions with alkenes (Scheme 2.1). Both cyclic and acyclic nitronates participated, thus providing a new functional group were the nitrogen atom existed at the center of an acetal (13). These compounds were subsequently referred to as nitroso acetals (14) or nitrosals (15). 

The nitroso acetals that result from the [3 + 2] cycloaddition of alkyl nitronates with dipolarophiles typically provide several characteristic spectroscopic signals for identification. As in the silyl counterparts, the O—N—O stretch in the alkyl nitroso acetals is observed in the IR ranges between 1000 and 1030 cm (Tables 2.22 and 2.23) (57,75-77). However, this resonance is usually not strong, and can be obscured by other functional group resonances with more substituted nitroso acetals. 

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