(1R*,3R*,7S*,9S*)-1,4,4-Trimethyl-9-(tert-butyldimethylsilyloxy)-e xo-11-oxatricyclo[5.3.1.0(2,6)]-undecan-3-ol, C19H36O3Si, Mr = 340.90, orthorhombic, Pbca, a = 10.411 (3), b = 13.275 (3), c = 29.085 (10) A, V = 4019 (2) A3, Z = 8, Dx (130 K) = 1.13 g cm-3, lambda(Mo K alpha) = 0.71069 A, mu = 1.24 cm-1, F(000) = 1504, T = 130 K, R = 0.077 for 1005 observed reflections with I greater than 3 sigma(I). The compound, whose connectivity was not readily apparent from spectroscopic and chemical information alone, possesses a tricyclic framework containing an O-bridged bicyclo[3.2.1]octane fused in a cis-exo manner to a cyclopentanol ring. Most noteworthy is the considerably lower polarity of this compound relative to its opposite cyclopentanol stereoisomer. The close proximity [2.78 (1) A] of the bridging O atom in the [3.2.1] system to the hydroxyl O atom on the five-membered ring is suggestive of an intramolecular hydrogen bond, although the H atom could not be located.