作者:M. Robert J. Vallée、Inga Inhülsen、Paul Margaretha
DOI:10.1002/hlca.200900202
日期:2010.1
synthesized 3‐(alk‐1‐ynyl)cyclohept‐2‐en‐1‐ones 1 and 2 leads to the selective formation of tricyclic head‐to‐head dimers. In the presence of 2,3‐dimethylbuta‐1,3‐diene, the (monocyclic) enone 1 affords trans‐fused 7‐alkynyl‐bicyclo[5.2.0]nonan‐2‐ones as major photoproducts, whereas photocycloaddition of benzocyclohept‐5‐en‐7‐one 2 to the same diene gives preferentially the eight‐membered cyclic allene 16 via
新合成的3-(alk-1-ynyl)cyclohept-2-en-1-ones 1和2的辐照(350 nm)导致三环头对头二聚体的选择性形成。在存在2,3-二甲基丁1,3-二烯的情况下,(单环)烯酮1提供反式融合的7-炔基-双环[5.2.0] nonan-2-酮作为主要的光产物,而苯并环庚酮的光环加成-5-烯-7-酮2到同一优先二烯给出八元环状丙二烯16 经由中间烯丙基炔丙基双自由基的“端至端”环化22。与酸接触时,环辛基1,2,5-三烯16异构化为环辛-1,3,5-三烯18。