Synthesis, Structure and Properties of (7)Heterohelicenes Possessing Phenolic Hydroxy Functions.

Photocyclization of 2,7-bis[3-(t-butyldimethylsilyloxy)phenylvinylene]benzo[1,2-b:4,3-b′]dithiophene affords three regioisomers of the bis(silyloxy)[7]thiaheterohelicenes together with the unexpected 4-phenyl-substituted [7]thiaheterohelicene. Cleavage of the silyl ethers gave the helical quinone, which includes ethanol as guest molecules to form a 1:1 inclusion complex.