Abstract
The main goal of the synthesis is to study the Photo-induced cyclization reaction of α- iodo cycloalkanones bearing an allenic side chain. We first use the α- iodo cycloalkanone compound 71a-b as starting material, introduce the side chain of allene from β-position successfully by 1,4-Michael addition and then follow with Photo-induced Electron Transfer（PET） cyclization reaction, we obtain the 5、5-fused, 6、5-fused bicycle compounds 73a-b and 74a-c. Besides, we compare the difference of reaction by using Iodide and Slow-addition radical cyclization. From the results, we conclude that the products are all the same. It is avoidable to use the reagent that generate radical because of the allenic side chain can proceed the Photo-induced Electron Transfer cyclization reaction. It is also more convenient of purification. We can construct the structure of 5、5-fused and 6、5-fused bicycle compounds efficient and take advantage of in the synthesis of natural compounds such as (+)-Axamide-4 or (+)-Axisonitrile-4.