gem-Dinitroalkanes (3) have been prepared by reaction of nitro olefins with organolithium reagents, followed by treatment with tetranitromethane. 2-Alkoxy-gem-dinitroalkanes (2) are obtained similarly by employing alkoxides as the basic addend. The preparation of 1-bromo derivatives of 2 and their reaction with bases are described. The 1H and I3C NMR spectra of 2 and 3 are presented and discussed.