TRANS-4-TERT-BUTYL-3-HYDROXY-5-CYCLOHEPTEN-1-ONE (2) AND TRANS-6-TERT-BUTYL-3-HYDROXY-2,7-DIMETHYL-4-CYCLOHEPTEN-1-ONE (5)

(2) C11H18O2, M(r) = 182.3, monoclinic, P2(1)/a, a = 7.463 (3), b = 9.776 (3), c = 14.955 (5) angstrom, beta = 97.33-degrees, V = 1082.2 angstrom 3, Z = 4, D(x) = 1.12 g cm-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 0.70 cm-1, F(000) = 400, room temperature, R = 0.041 for 480 observed reflections. (5) C13H22O2, M(r) = 210.3, orthorhombic, Pnab, a = 9.747 (1), b = 10.724 (2), c = 24.365 (4) angstrom, V = 2546.8 angstrom 3, Z = 8, D(x) = 1.10 g cm-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 0.67 cm-1, F(000) = 928, room temperature, R = 0.037 for 521 observed reflections. In both (2) and (5) the hydroxyl group is trans with respect to the tert-butyl group. In (2) pairs of molecules are linked via hydrogen bonds [O...O (1-x, 1-y, 1-z) 2.809 (7) angstrom] to form centrosymmetric dimers, while in (5) molecules are hydrogen bonded [O...O(x, -0.5+y, 1.5-z) 2.847 (7) angstrom] through 2(1) screw axes to form infinite chains. The highly strained seven-membered ring in (2) has a boat-type conformation and in (5) it has a sofa-type conformation.