5-[(1R,2R,4R)-2-Meth­oxy-1,7,7-tri­methylbi­cyclo­[2.2.1]hept-2-yl]-1H-tetra­zole

The title compound, C(12)H(20)N(4)O, undergoes a phase transition on cooling. The room-temperature structure is tetra­gonal (P4(3)2(1)2, Z′ = 1), with the meth­oxy­bornyl group being extremely disordered. Below 213 K the structure is ortho­rhom­bic (P2(1)2(1)2(1), Z′ = 2), with ordered mol­ecules. The two independent mol­ecules (A and B) have very similar conformations; significant differences only occur for the torsion angles about the C(born­yl)—C(tetra­zole) bonds. The independent mol­ecules are approximately related by the pseudo-symmetry relation: x(B) = −1/4 + y(A), y(B) = 3/4 - x(A) and z(B) = 1/4 + z(A). In the crystal, mol­ecules are connected by N—H⋯N hydrogen bonds between the tetra­zole groups, forming a pseudo-4(3) helix parallel to the c-axis direction. The crystal studied was a merohedral twin with a refined twin fraction value of 0.231 (2).