Nitroalkenes methylene activation

When a-tethered nitroalkenes bearing three or four methylene chains and ester-activated dipolarophiles react with vinyl ethers, spiro mode tandem cycloaddition takes place to give tricyclic spiro nitroso acetals in good yield and high diastereoselectivity (Scheme 8.46).184... 

Yuan, C., and Li, C., SIndies on organophosphorus compounds. Part 67. Reactions of a-nitroalkenes with compounds bearing active methylene groups. A novel and convenient synthesis of 2-isoxazoline derivatives, Phosphorus, Sulfur Silicon Relat. Elem., 78, 47, 1993. 

Nitroalkenes as Acceptors. The organocatalytic asymmetric Michael addition of activated methylenes to nitroalkenes is an important carbon-carbon bond-forming reaction, which provides access to synthetically useful enantioen-riched nitroalkanes. In 2003, Takemoto and co-workers [77] disclosed the first highly... 

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