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[摘要]:We report a stereodivergent synthesis of both enantiomers of glycero-allo-heptose from 2,2-dimethyl-1,3-dioxan-5-one, a readily available nonchiral scaffold, and from two different synthetic equivalents of glyoxal: dimethoxyacetaldehyde and 1,3-dithiane-2-carboxaldehyde. The short synthetic sequence involves first a proline-mediated, and then a lithium enolate mediated aldol reaction at the alpha-and alpha'-positions of the dioxanone ring, respectively, and demonstrates the complementary nature of organocatalysis and metal enolate based methods. |
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