Scheme 7.

a) Isomeric molecules of benzo[a]pyrene; b) synthesis of compound 39; c) synthesis of compound 44. NaH: sodium hydride; (C₂H₅O)₂CO: diethyl carbonate; NaOMe: sodium methanolate; SOCl₂: sulfinyl chloride; CH₂N₂: diazomethane; DDQ: 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone.^{[ 48 ]}