Synthesis of 2H-Chromenes through the Reduction of Chromones with 9-BBN.

T Eguchi, Y Hoshino

Index: Eguchi; Hoshino Bulletin of the Chemical Society of Japan, 2001 , vol. 74, # 5 p. 967 - 970

Full Text: HTML

Citation Number: 8

Abstract

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 ...