Nitroalkenes 3-hydroxylation reactions

Beak used this method in a synthesis of (-)-paroxetine 97 (Paxil or Seroxat), a selective serotonin reuptake inhibitor.9 Lithiation of 92 with n-BuLi-(-)-sparteine and addition of the product 93 to the nitroalkene 94 yields the protected Z-enamine 95, as usual for reactions of lithiated allylamides, in >94% ee. Hydrolysis and reduction of the product, followed by mesylation and cyclisation gave the fnms-substituted piperidine 96. Displacement of the hydroxyl group by sesamol yielded (-)-paroxetine 97. 

The Henry reaction is a base-catalyzed C-C bond-forming reaction between nitroalkanes and aldehydes or ketones. It is similar to the aldol addition, and is also referred to as the nitroaldol reaction. Since its discovery in 1895 [1] the Henry reaction has become one of the most useful reactions for the formation of C-C bonds, and most particularly for the synthesis of P-nitroalcohol derivatives [2]. The general features of this reaction are (i) the potential offered by the nitro and hydroxyl groups on the products for transformation into other compound families such as P-amino alcohols, P-amino acids, or nitroalkenes (ii) only a catalytic amount of base is required (iii) up to two contiguous stereogenic centers may be created in a single step concomitantly to the C-C bond formation. Several recent reviews with a focus on the asymmetric Henry reaction and its applications have appeared [3j. 

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