Adducts from quinones and diazoalkanes. Part VIII. Further reactions of 2-methyl-1,4-naphthoquinone with carbanions

Abstract

3-Methyl-1,4-naphthoquinon-2-ylmethyl carbanion (I) adds to 2-methyl-1,4-naphthoquinone giving a fluorene derivative (V) along with the related tetraketone (VII). The methylenedinaphthoquinone (III) is also formed but the expected xanthen derivative (IV) still eludes isolation though it must be an important product since it is readily trapped by an excess of 2-methylnaphthoquinone as the bridge compound (VIa) with a bicyclo[3,2,1]octane nucleus. Another product with a bicyclo[3,2,1]octane nucleus is simultaneously produced and is shown to have structure (X). The stereochemistry of these reactions is discussed.