Abstract
Dimethyl 1, 2, 3, 10-tetrahydro-4β, 10α-dimethyl-4H-fluorene-4α, 6-dicarboxylate and its hydrogenated stereoisomers were nitrated with conc. HNO3-Ac2O to give mononitro compound as a single product. Namely, ⊿5-diester (X) was nitrated to give only 12-nitro compound (XI) and, in contrast, four possible stereoisomers due to the asymmetric centers at C-5 and C-6 of the saturated diester (XVII, XVIII, XIX, and XX) gave only 13-nitro compounds (XXI, XXII, XXIII, and XIV, respectively). Accordingly, 12-and 13-substituted (NO2, NH2, OH, and OMe) compound could be optionally obtained herein.
