Photoannelation Reactions of 3-(Alk-1-ynyl)cyclohept-2-en-1-ones
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