Cycloadditions of Allylsilanes, Part 12. Regio- and Stereoselective Transformations of Silylbicyclo[n.3.0]alkanes
作者:Hans-Joachim Knölker、Norbert Foitzik、Christoph Gabler、Regina Graf
DOI:10.1055/s-1999-3684
日期:——
Lewis acid promoted [3 + 2] cycloaddition of 1-acetylcycloalkenes and allylsilanes provides the silylbicyclo[n.3.0]-alkanes 4 and 5. The sequence of regioselective Bayer-Villiger oxidation and elimination of acetic acid affords the 3-silylbicyclo[3.3.0]oct-1(5)-enes 8a and 9a and the 8-(triphenylsilyl)bicyclo[4.3.0]non-1(6)-ene (8b). Epoxidation and catalytic hydrogenation of these olefins proceeds with complete stereoselectivity anti relative to the silyl substituent. Ozonolysis of 8b leads to 3-(triphenylsilyl)cyclononane-1,5-dione (15).
在路易斯酸的促进下,1-乙酰基环烯烃和烯丙基硅烷发生[3 + 2]环加成反应,生成硅基双环[n.3.0]烷烃 4 和 5。通过区域选择性拜耳-维里格氧化和消除乙酸的顺序,可以得到 3-硅基双环[3.3.0]辛-1(5)-烯 8a 和 9a,以及 8-(三苯基硅基)双环[4.3.0]壬-1(6)-烯 (8b)。这些烯烃的环氧化和催化氢化反应具有完全的立体选择性,与硅烷取代基相反。对 8b 进行臭氧分解可得到 3-(三苯基硅基)环壬烷-1,5-二酮 (15)。