Reduction Henry reaction, stereoselectivity

In recent years, the importance of aliphatic nitro compounds has greatly increased, due to the discovery of new selective transformations. These topics are discussed in the following chapters Stereoselective Henry reaction (chapter 3.3), Asymmetric Micheal additions (chapter 4.4), use of nitroalkenes as heterodienes in tandem [4+2]/[3+2] cycloadditions (chapter 8) and radical denitration (chapter 7.2). These reactions discovered in recent years constitute important tools in organic synthesis. They are discussed in more detail than the conventional reactions such as the Nef reaction, reduction to amines, synthesis of nitro sugars, alkylation and acylation (chapter 5). Concerning aromatic nitro chemistry, the preparation of substituted aromatic compounds via the SNAr reaction and nucleophilic aromatic substitution of hydrogen (VNS) are discussed (chapter 9). Preparation of heterocycles such as indoles, are covered (chapter 10). 

Stereoselective synthesis of highly functionalized azatricycles (e.g., 75) has been achieved by copper-catalysed Henry reaction of enals with nitromethane, zinc reduction of the nitro group and subsequent tosylation, followed by iodocyclization. The iodine is easily removed afterwards by hydrogenation, or can be used to introduce other functionality, such as by epoxidation of the adjacent alcohol. 

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