| Abstract
| - A series of novel 5-aryl-4-aryloxymethyl-3-diazotetrahydrofuran-2-ones (12, 24, and 35a/b) havebeen prepared and found to undergo regio- and stereoselective C−H insertion reactions to afford2,6-diaryl-3,7-dioxabicyclo[3.3.0]octane-8-ones (18, 26, and 36a/b) with endo,exo stereochemistry.Subsequent reduction of the lactone ring and cyclization of the resulting diols 27 and 37a/b permittedthe synthesis of three endo,exo-furofuran lignans: asarinin (2), fargesin (3), and epimagnolin A(4). En route to the key diazo compounds 24 and 35a/b, a modified procedure for the Ghosezketeniminium−olefin cyclization was developed, which was required to minimize the decompositionof acid-sensitive functional groups such as electron-rich benzylic ethers that were present in thetarget compounds 2−4.
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