Tetrahedron

Addition of cyclopentadiene and 2-trimethylsilyloxyfuran to quinones bearing a menthyl ester chiral auxiliary

MA Brimble, LJ Duncalf, DCW Reid, TR Roberts

Index: Brimble, Margaret A.; Duncalf, Letecia J.; Reid, David C. W.; Roberts, Tabitha R. Tetrahedron, 1998 , vol. 54, # 20 p. 5363 - 5374

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Citation Number: 17

Abstract

Addition of cyclopentadiene to 2-carbomethoxy-1, 4-benzoquinone 9 afforded Diels-Alder adduct 10 using the Lewis acids ZnCl2 and ZnBr2 whereas the fragmenatation product 11 was the major product when using SnCl4 and TiCl4. Addition of cyclopentadiene to 1, 4- benzoquinone 8 bearing a menthyl ester at C-2 afforded Diels-alder adduct 12 in moderate diastereomeric excess using ZnCl2 and ZnBr2 as Lewis acids. Use of TiCl4 and SnCl4 ...