Access to 2,6-Disubstituted 4-Oxopiperidines Using a 6-<i>Endo</i>-<i>trig</i> Cyclization: Stereoselective Synthesis of Spruce Alkaloid and (+)-241D
作者:Alexander H. Harkiss、Andrew Sutherland
DOI:10.1021/acs.joc.7b02799
日期:2018.1.5
providing the corresponding 4-oxopiperidines in high yields (80–89%). Stereoselective reduction of the 2,6-cis-disubstituted 4-oxopiperidines then gave the 2,4,6-cis,cis-trisubstituted 4-hydroxypiperidines in high diastereoselectivity. The general nature of this approach was demonstrated with the synthesis of the natural products, spruce alkaloid and (+)-241D.
所述的合成途径的顺-2-甲基-4-氧代-6-烷基哌啶已经使用6-开发内切- trig的环化(ë)-enones。发现碱介导的分子内环化对于烷基和芳基取代的烯酮都是普遍的,以高收率(80-89%)提供相应的4-氧代哌啶。2,6-的立体选择性还原顺式二取代的4-氧代哌啶然后,得到2,4,6-顺式,顺式在高非对映选择性-三取代4- hydroxypiperidines。天然产物云杉生物碱和(+)-241D的合成证明了这种方法的一般性质。