Process for preparing 6helicenes by photocyclization

摘要

In the present invention, there is disclosed a process for preparing racemic [6]helicene and substituted analogs thereof by photocyclization in the presence of nonpolar aprotic solvents, a catalytic amount of iodine and UV/Vis radiation wherein the invention is characterized in that the photocyclization is carried out in the environment of a microwave field with frequency in the range of 500 MHz to 10 GHz until the double photocyclization from the starting compounds of the general formula I is achieved.