ol2016934_si_001.pdf (3.35 MB)
Synthesis of γ-Benzopyranone by TfOH-Promoted Regioselective Cyclization of o-Alkynoylphenols
journal contribution
posted on 2011-09-02, 00:00 authored by Masahito Yoshida, Yuta Fujino, Takayuki DoiRegioselective cyclization of o-alkynoylphenols forming γ-benzopyranones has been demonstrated. Trifluoromethanesulfonic acid (TfOH) induced 6-endo cyclization of o-alkynoylphenols without forming 5-exo cyclized benzofuranone derivatives to provide the corresponding γ-benzopyranones in high yields.