4,9-Dimethoxynaphtho2,3-bfuran 9 was obtained in 91 yield via the reductive methylation of naphtho2,3-bfuran-4,9-dione 2. After treatment of 9 with butyllithium, the mixture was allowed to react with N,N-dimethylacetamide, followed by oxidization with cerium(IV) diammonium nitrate to give 2-acetylnaphtho2,3-bfuran-4,9-dione 1. 2-Formylnaphtho2,3-bfuran-4,9-dione 13 and 2-trimethylsilylnaphtho2,3-bfuran-4,9-dione 14 were also obtained from 9 by a similar method. The halodesilylations of 14 easily gave 2-iodonaphtho2,3-bfuran-4,9-dione 16, 2-bromonaphtho2,3-bfuran-4,9-dione 17, and 2-chloronaphtho2,3-bfuran-4,9-dione 18 in 82, and 93 and 83 yield, respectively. Furthermore, the nitrodesilylation of 14 gave 2-nitronaphtho2,3-bfuran-4,9-dione 3 in 77 yield. References: 13
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