... Volume: Page: ... 15 The six-membered ring O(1)−C(11)−C(e2)−C(e1)−C(13)−C(12) adopts an envelope conformation with O(1) at the flap ... angles across C(13)−C(e1) and C(e1)−C(e2) (Table 4); the ring-puckering parameters [Q = 0.614(7) Å, θ = 53.7(7)°, φ = 358 ...