Cascade radical-mediated cyclisations with conjugated ynone electrophores. An approach to the synthesis of steroids and other novel ring-fused polycyclic carbocycles
作者:Gerald Pattenden、Davey A. Stoker、Nicholas M. Thomson
DOI:10.1039/b703373g
日期:——
A cascade radical-mediated Diels-Alder reaction with the iododienynone 16b produced the tricyclic ketone 17 (22%). By contrast, treatment of the substituted furans 36 and 47 with Bu(3)SnH-AIBN, instead led to the tetracycles 44 and 58 respectively, rather than the anticipated oestranes, i.e. 38 and 48. In a separate study, attempted cascade radical-mediated cyclisations from the ortho-aryl substituted
与碘二烯酮16b的级联自由基介导的Diels-Alder反应产生了三环酮17(22%)。相比之下,用Bu(3)SnH-AIBN处理取代的呋喃36和47分别导致四环化合物44和58,而不是预期的雌激素,即38和48。在另一项研究中,尝试了级联自由基-由邻芳基取代的碘二烯酮72和73介导的环化反应,最终导致环D芳族甾体7取代,分别给出大环酮76或新型桥联三环77/82,这取决于是使用苯还是庚烷作为溶剂在反应中。