作者:Wen-Ju Bai、Jason C. Green、Thomas R. R. Pettus
DOI:10.1021/jo201971g
日期:2012.1.6
l-lactic-acid-derived exocyclic enol ether. Novel reactions of special note include a diastereoselective reduction of a chroman spiroketal by combination of borontrifluoride etherate and triethyl silane, along with oxidative rupture of a chroman etherial ring into the corresponding p-quinone by argentic oxide (AgO). In addition, an unusual intramolecular etherification of a 3° alcohol caused by cerium ammonium
对-旋螺酮A和C的立体发散性总合成都在11个容器中完成,总总收率(A + C)约为24%。这些合成方法在扩展共轭的γ-δ不饱和邻醌甲基化物和1-乳酸衍生的环烯醇醚的替代物之间采用相同的逆需求Diels-Alder反应。特别值得注意的新反应包括通过三氟化硼醚化物和三乙基硅烷的组合将苯并吡喃非对映异构体非对映选择性还原,以及苯并三氧化二砷(AgO)将苯并二氢吡喃醚环氧化断裂为相应的对苯醌。另外,不寻常的分子内 观察到由硝酸铈铵引起的3°醇的醚化。