We apply symmetry theorems to the problem of heteronuclear dipolar recoupling in the presence of magic-angle spinning in solid-state NMR. Examples are shown in which the C-13 NMR signal is acquired while rotor-synchronized pulse sequences with the symmetry R18(1)(7) or R18(2)(5) are applied to the H-1 spins. This allows recoupling of heteronuclear dipolar interactions combined with homonuclear decoupling of the irradiated H-1 spins. The structure of the C-13 NMR spectrum is sensitive to bond lengths and bond angles. A two-dimensional procedure is described for applications to multiply isotopically labelled systems.