Foresti Elisabetta, Palmieri Gianni, Petrini Marino, Profeta Roberto
Dipartimento di Chimica G. Ciamician, Università di Bologna, via Selmi, 2. 1-40126 Bologna, Italy.
Org Biomol Chem. 2003 Dec 7;1(23):4275-81. doi: 10.1039/b309211a. Epub 2003 Oct 23.
Optically active syn-alpha-amidoalkylphenyl sulfones can be prepared from chiral aldehydes in anhydrous conditions using benzenesulfinic acid. These sulfones in basic conditions give N-acylimines that react with sodium methanenitronate to afford the corresponding nitro adducts with high anti diastereoselectivity. PM3 semiempirical calculations provide a rationale for the observed opposite stereoselectivity. The obtained nitro derivatives undergo a Nef reaction followed by a methylation giving optically active beta-hydroxy-alpha-amino acid and alpha,beta-diamino acid esters in good yield. These amino acid derivatives are important building blocks for the preparation of biologically active compounds.
光学活性的顺式-α-酰胺基烷基苯基砜可在无水条件下由手性醛与苯亚磺酸制备。这些砜在碱性条件下生成N-酰基亚胺，其与甲烷亚硝基钠反应，以高反式非对映选择性得到相应的硝基加合物。PM3半经验计算为观察到的相反立体选择性提供了理论依据。所得到的硝基衍生物经过涅夫反应，然后甲基化，以良好的产率得到光学活性的β-羟基-α-氨基酸和α,β-二氨基酸酯。这些氨基酸衍生物是制备生物活性化合物的重要结构单元。
