The lithiation of 1H, 3H-benzo [de] isochromene () with lithium and a catalytic amount of 4, 4′-di-tert-butylbiphenyl (DTBB, 5% molar) in THF at− 50° C gives dianionic intermediate, which by reaction with different electrophiles {H2O, D2O, tBuCHO, PhCHO, Me2CO,(CH3CH2) 2CO,[CH3 (CH2) 4] 2CO,(CH2) 5CO,(CH2) 7CO,(−)-menthone} at the same temperature followed by hydrolysis leads to functionalised alcohols. If after addition ...