title: (3aS,4S,6S,7aR)-Hexahydro-3a,5,5-trimethyl-2-phenyl-4,6-methano-1,3,2-benzodioxaborole.
abstract: The mol-ecule of the title compound, C(16)H(21)BO(2), comprises a chiral fused tricyclic system containing five-membered (1,3,2-dioxaborolane), six-membered (cyclo-hexa-ne) and four-membered (cyclo-butane) rings. The 1,3,2-dioxaborolane ring is almost planar (r.m.s. deviation = 0.035 Å), and the syn H and Me substituents at this ring are in an eclipsed conformation. The cyclo-hexane and cyclo-butane rings adopt sofa and butterfly conformations, respectively. The B atom has a trigonal-planar configuration (sum of the bond angles = 360.0°). The phenyl ring is practically coplanar with the 1,3,2-dioxaborolane ring [dihedral angle between the ring planes = 1.96 (8)°]. The absolute structure was determined from the known configuration of (+)-pinanediol which was used in the synthesis. In the crystal, weak C-H⋯π(Ph) inter-actions occur.
authors.affiliation: Department of Chemistry, Faculty of Science and Technology, University of Tromsø, N-9037 Tromsø,  Norway.
authors.forename: Tore
authors.initials: T
authors.lastname: Lejon
authors.forename: Olga V
authors.initials: OV
authors.lastname: Gozhina
authors.forename: Victor N
authors.initials: VN
authors.lastname: Khrustalev