Stereoselective Synthesis of Functionalized <i>trans</i>-2,5-Disubstituted Tetrahydrofurans
作者:Ronaldo A. Pilli、Valéria B. Riatto、Ivo Vencato
DOI:10.1021/ol991194u
日期:2000.1.1
derived from (S)-glutamic acid, afforded trans- and cis-2,5-disubstituted tetrahydrofurans (trans/cis ratio: R = H, 2:1; R = Me, 8:1; R = Br, 10:1) after desilylation with aqueous HF/CH3CN. Chromatographic separation and LiBH4 reduction allowed the efficient preparation of the corresponding trans-2,5-disubstituted tetrahydrofuran diols and the recovery of the chiral auxiliary.
[反应:请参见文本]将N-乙酰基,N-丙酰基和N-溴乙酰基(R)-恶唑烷-2-酮的烯醇钛添加到衍生自(S)-谷氨酸的γ-乳糖醇2中,用HF / CH3CN水溶液进行甲硅烷基化后,反式和顺式2,5-二取代的四氢呋喃(反式/顺式比:R = H,2:1; R = Me,8:1; R = Br,10:1)。色谱分离和LiBH4还原可以有效制备相应的反式2,5-二取代四氢呋喃二醇,并可以回收手性助剂。