Novel stereoconvergent transformation of 1,2a-disubstituted 1,2,2a,8b-tetrahydro-3H-benzo[b]cyclobuta[d]pyran-3-ones to 1,3-disubstituted 1,2,4a,9b-tetrahydrodibenzofuran-4-ols and its application to the second-generation synthesis of (+/-)-linderol A.
1,2a-Disubstituted 1,2,2a,8b-tetrahydro-3H-benzo[b]cyclobuta[d]pyran-3-ones bearing an electron-withdrawing group at the 2a-position were treated with two equivalents of dimethylsulfoxonium methylide to give r-1,t-4a,t-9b-1,3-disubstituted 1,2,4a,9b-tetrahydrodibenzofuran-4-ols stereoconvergently regardless of the stereochemistry of the 1-position on the benzocyclobutapyran ring. This methodology was applied to the second-generation synthesis of (+/-)-linderol A, a melanin biosynthesis inhibitory natural product.
Yamashita
Masayuki
M
Department of Functional Molecular Chemistry, 21st COE Program, Kyoto Pharmaceutical University, Misasagi-Nakauchi 5, Yamashina, Kyoto 607-8414, Japan.
Inaba
Tomoki
T
Nagahama
Masaki
M
Shimizu
Takashi
T
Kosaka
Sachiko
S
Kawasaki
Ikuo
I
Ohta
Shunsaku
S
D001572:Benzofurans / Q000138:chemical synthesis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D011714:Pyrans / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
D001572:Benzofurans; D011714:Pyrans; C429131:linderol A; C023614:dibenzofuran