Fig. 1: Background and strategy overview.

a, C(sp2). Benzenoids as parts of the 2D honeycomb structure of graphene; 3D topology of π-helicenes. b, C(sp3). Diamondoids with face-fused cages superimposable on the 3D diamond lattice. c, Isomerism, symmetry and σ-helicity of tetramantanes. d, Synthetic strategy. Adamantalogous cage extension for the total synthesis of skew-tetramantane, diamond’s chiral core.