Chromones were regioselectively reduced to 2H-1-benzopyrans through the 1, 2-addition of 9-borabicyclo [3.3. 1] nonane. Although transition-metal complexes did not have a catalytic effect on the reaction, only by using palladium (II) chloride, could both 2H-1-benzopyran and dihydro-1-benzopyran be obtained to a similar extent. Also, the reduction of chromone using other organoboranes led not to 2H-1-benzopyran, but rather to chromanone through the ...