Reactions of methylcubane (1) with the tert-butoxyl radical (t-BuO.), with cytochrome P-450 enzymes, and with a methane monooxygenase (MMO) system have been studied. For the purpose of product characterization, authentic samples of 2-methylcubyl and 4-methylcubyl derivatives were prepared. 2-Methylcubanecarboxylic acid (9b) is a new compound prepared from cubanecarboxylic acid. The key synthetic reactions were (1) metalation and subsequent iodination of the 2-position of (diisopropylcarbamoyl)cubane to effect the initial functionalization, (2) lithium-for-iodine exchange and methylation followed by reduction to give 2-methyl-1-[(diisopropylamino)methyl]-cubane, and (3) dimethyldioxirane oxidation of this amine to give 9b. The known 4-methylcubanecarboxylic acid (9d) was prepared here by a route related to that employed for 9b.