Studies toward the Photochemical Synthesis of Functionalized [5]- and [6]Carbohelicenes

摘要

An efficient route to nonsymmetrical helical menthyl esters by means of an oxidative photocycliza-tion reaction of dissymmetric bis-stilbenes is reported. The developed route allows the introductionof functionality on rings A, E, or F, and the influence of the substituent pattern on the photochemicalreaction has been examined. Diastereoselectivity is observed when a double chiral induction strategywith dimenthyl helicene esters synthesized in a 70:30 ratio of isomers is used.