Nitroalkanes cyclic, synthesis

The Ter Meer reaction has not been widely exploited for the synthesis of m-dinitroaliphatic compounds. This is partly because the Kaplan-Shechter oxidative nitration (Section 1.7) is more convenient, but also because of some more serious limitations. The first is the inability to synthesize internal em-dinitroaliphatic compounds functionality which shows high chemical stability and is found in many cyclic and caged energetic materials. Secondly, the em-nitronitronate salts formed in the Ter Meer reactions often need to be isolated to improve the yield and purity of the product. Dry em-nitronitronate salts are hazardous to handle and those from nitroalkanes like 1,1,4,4-tetranitrobutane are primary explosives which can explode even when wet. Even so, it is common to use conditions that lead to the precipitation of gem-nitronitronate salts from solution, a process that both drives the reaction to completion and also provides isolation and purification of the product salt by simple filtration. Purification of em-nitronitronate salts by filtration from the reaction liquors, followed by washing with methanol or ethanol to remove occluded impurities, has been used, although these salts should never be allowed to completely dry. 

Nitroalkanes provide products, which are especially versatile building blocks, since the nitro group introduced can be converted to several other functionalities. The examples shown in Eq. 58-61 include synthesis of regioisomeric 7-nitro-4-oxo-esters, of a cyclic system 141, and of a propenyl substituted derivative — all proceeding with good overall yield from easily available, inexpensive starting materials83 84 . 

The addition of nitronates to alkenes opens up a route to isoxazolidines, useful precursors for the synthesis of 2-isoxazolines. Tandem [4+2]/[3+2] cycloaddition reactions of nitroalkanes involving cyclic alkyl nitronates have been reported by Denmark et al. ... 

Bhattacharjya and co-workers reported the synthesis of chiral cyclic ether fused isoxazolines via INOC of allyl glucose derivatives [136]. The pentaallyl nitroalkane 131 when subjected to nitrile oxide generation under Mukaiyama... 

In addition to cyclic derivatives, this chemistry has also been used for the preparation of Q ,/3-unsaturated oximes from either nitroalkanes or 1,2-oxazine IV-oxides. Equation 27 shows the synthesis of /3-functionalized Q ,/3-unsaturated oximes from nitroalkanes. 

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