Stereoselective Synthesis of the C(1)−C(19) Fragment of Tetrafibricin
作者:Ricardo Lira、William R. Roush
DOI:10.1021/ol0629869
日期:2007.2.1
[reaction: see text] A stereoselectivesynthesis of the C(1)-C(19) fragment of tetrafibricin has been accomplished via a highly diastereoselective double allylboration reaction of 6-8 and an iodonium ion promoted urethane cyclization for the installation of the C(15) alkoxy function in 3.
[反应:见正文] 四纤维星的 C(1)-C(19) 片段的立体选择性合成是通过 6-8 的高度非对映选择性双烯丙基硼化反应和碘鎓离子促进的氨基甲酸酯环化以安装 C 来完成的。 (15) 3中的烷氧基官能团。
(Diisopinocampheyl)borane-Mediated Reductive Aldol Reactions of Acrylate Esters: Enantioselective Synthesis of <i>Anti</i>-Aldols
作者:Christophe Allais、Philippe Nuhant、William R. Roush
DOI:10.1021/ol401679g
日期:2013.8.2
The (diisopinocampheyl)borane promoted reductive aldol reaction of acrylate esters 4 is described. Isomerization of the kinetically formed Z(O)-enolborinate 5Z to the thermodynamic E(O)-enolborinate 5E via 1,3-boratropic shifts, followed by treatment with representative achiral aldehydes, leads to anti-alpha-methyl-beta-hydroxy esters 9 or 10 with excellent diastereo- (up to >= 20:1 dr) and enantioselectivity (up to 87% ee). The results of double asymmetric reactions of 5E with several chiral aldehydes are also presented.
10.15227/orgsyn.92.0038
作者:Abbott, Jason R.、Allais, Christophe、Roush, William R.