Cruz-Montañez Alejandra, Morales-Rivera Keyla F, Torres Wildeliz, Valentín Elizabeth M, Rentas Jaileen, Prieto José A
Department of Chemistry, University of Puerto Rico, Río Piedras Campus. PO Box 23346 San Juan, PR 00931.
Department of Chemistry, University of Puerto Rico, Mayagüez Campus, PO Box 9000, Mayagüez, PR 00681-9000.
Inorganica Chim Acta. 2017 Nov 1;468:28-37. doi: 10.1016/j.ica.2017.06.042. Epub 2017 Jun 15.
The enantioselective synthesis of polypropionates continues to be an attractive realm for the synthetic chemists mostly due to the challenges presented by the number of consecutive stereogenic centers contained within the aliphatic chain. Over the years, our laboratory has developed an epoxide-based three-step reiterative methodology for the construction of these targets, with the ultimate goal that the approach could be extended to the synthesis of polypropionate-containing natural products. The key steps include the diastereoselective epoxidation of allylic and homoallylic alcohols, and the regioselective cleavage of 2-methyl-3,4-epoxy alcohols. The choice of the organometallic reagent, and the cis/trans geometry of the chiral epoxide can be used to control both the relative and absolute configuration of the resulting propionate unit, allowing our approach to be applied in the synthesis of advanced fragments. Additionally, the combination of our first- and second-generation methodologies permits the incorporation of different variations at the methyl moiety.
聚丙酸酯的对映选择性合成一直是合成化学家们感兴趣的领域，这主要是因为脂肪链中所含连续手性中心的数量带来了挑战。多年来，我们实验室开发了一种基于环氧化合物的三步迭代方法来构建这些目标分子，最终目标是将该方法扩展到含聚丙酸酯天然产物的合成。关键步骤包括烯丙醇和高烯丙醇的非对映选择性环氧化，以及2-甲基-3,4-环氧醇的区域选择性裂解。有机金属试剂的选择以及手性环氧化合物的顺式/反式几何结构可用于控制所得丙酸酯单元的相对和绝对构型，使我们的方法能够应用于高级片段的合成。此外，我们第一代和第二代方法的结合允许在甲基部分引入不同的变体。
