Lewis Acid-Mediated Stereoselective Spiroannelation: A Facile Access to Aphidicolane and Stemodane B/C/D Ring Systems.
作者:Tetsuaki TANAKA、Osamu OKUDA、Kazuo MURAKAMI、Hitoshi YOSHINO、Hidenori MIKAMIYAMA、Atsushi KANDA、Sang-Wong KIM、Chuzo IWATA
DOI:10.1248/cpb.43.1017
日期:——
A novel and stereoselective spiroannelation reaction was developed. Treatment of the suitably functionalized cyclohexene derivative (3) with trimethylsilyl trifluoromethanesulfonate (TMSOTf) afforded the spiro[5.5]undecanes 4A and 5S exclusively. Changing the solvent from CH2Cl2 to CH3CN or THF increased the stereoselectivity; predominant formation of 4A in CH3CN and 5S in THF was observed. The spirocyclic compounds 4A and 5S were transformed into the tricyclo[6.3.1.01, 6]dodecane derivatives (19A and 27S) corresponding to the B/C/D rings of aphidicolanes (1) and stemodanes (2).
开发了一种新颖且具立体选择性的螺环化反应。将适当功能化的环己烯衍生物(3)与三甲基氟化硫酸酯(TMSOTf)反应,独占性地生成了螺[5.5]十一烷4A和5S。将溶剂从CH2Cl2更改为CH3CN或THF后,立体选择性增强;在CH3CN中主要生成4A,而在THF中主要生成5S。螺环化合物4A和5S被转化为对应于蚜虫醇(1)和干茎烷(2)B/C/D环的三环[6.3.1.0^1,6]十二烷衍生物(19A和27S)。