The thermonuclear burn-up of highly compressed deuterated methane (CD4) is considered in the spherical geometry. The minimal required values of the burn-up parameter x = 0rf are determined for various temperatures T and densities 0. It is shown that thermonuclear burn-up in CD4 becomes possible in practice if its initial density 0 exceeds 5 × 103 g cm-3. Burn-up in CD2 T2 methane requires significantly ( 100 times) lower compressions. The developed approach can be used in order to compute the critical burn-up parameters in an arbitrary fuel which contains deuterium.