The lithiation of 1H,3H-benzo[de]isochromene (6) with lithium and a catalytic amount of 4,4'-di-tert-butylbiphenyl (DTBB, 5% molar) in THF at -50 o C gives dianionic intermediate 7, which by reaction with different electrophiles {H 2 O, D 2 O, t BuCHO, PhCHO, Me 2 CO, (CH 3 CH 2 ) 2 CO, [CH 3 (CH 2 ) 4 ] 2 CO, (CH 2 ) 5 CO, (CH 2 ) 7 CO, (-)-menthone} at the same temperature followed by hydrolysis leads to functionalised alcohols 8. If after addition of a carbonyl compound as the first electrophile [ t BuCHO, (CH 2 ) 5 CO, (-)-menthone], the resulting dialcoholate 9 is allowed to react at 0 o C, a second lithiation takes place to give intermediate 10 which by reaction with a second electrophile [H 2 O, t BuCHO, (CH 2 ) 5 CO, CO 2 ], yields, after hydrolysis, 1,8-difunctionalised naphthalenes 11. Cyclization under acidic conditions of diols 8e-i gives oxygen-containing eight-membered heterocycles, which are homologous to the starting material 6.