A new benzoangelicin with strong photobiological activity

Benzoangelicins 4–6 were synthesized in good yields from 7-hydroxy-5-methoxy-4-methylcoumarin (1). In the absence of UVA radiation, compounds 5 and 6 were only weakly active against HL60 and HeLa tumour cells; in its presence, compound 6 was 10 times more active than the reference compound 8-methoxypsoralen. None of 4–6 exhibited cutaneous phototoxicity. Scheme 1. Reagents: (a) 2-chlorocyclohexanone, K2CO3, Me2CO, reflux; (b) NaOH, reflux; (c) DDQ, benzene, reflux; (d) HI, AcOH, Ac2O, reflux; (e) 3-chloro-N,N-dimethylpropylamine, K2CO3, HMPA, Me2CO, reflux.