title: Investigations into the construction of the penta-substituted ring C of Neosurugatoxin - a crystallographic study.
abstract: The crystal structures of three cyclo-penta-[c]furans with various substituents at the 4-, 5- and 6-positions of the ring system are reported, namely, (±)-(3aR,4S,5S,6aS)-4-methyl-5-phenyl-hexa-hydro-1H-cyclo-penta-[c]furan-4,5-diol, C14H18O3, (I), (±)-(3aR,4S,5S,6aS)-4-benz-yloxy-4-methyl-5-phenyl-hexa-hydro-1H-cyclo-penta-[c]furan-5-ol, C21H24O3, (II), and (±)-(1aR,1bS,4aR,5S,5aR)-5-benz-yloxy-5-methyl-5a-phenyl-hexa-hydro-2H-oxireno[2',3':3,4]cyclopenta-[1,2-c]furan, C21H22O3, (III). The dominant inter-action in (I) and (II) is an O-H⋯O hydrogen bond across the bicyclic 5,5-ring system between the non-functionalized hy-droxy group and the tetra-hydro-furan O atom, which appears to influence the envelope conformations of the fused five-membered rings, whereas in (III), the rings have different conformations. A weak intra-molecular C-H⋯O inter-action appears to influence the degree of tilt of the phenyl ring attached to the 5-position and is different in (I) compared to (II) and (III).
authors: Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland; Division of Chemistry and Environmental Science, School of Science and the Environment, Faculty of Science and Engineering, Manchester Metropolitan University, John Dalton Building, Chester Street, Manchester M1 5GD, England.
authors: Alan M
authors: AM
authors: Jones
authors: Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland.
authors: John M D
authors: JM
authors: Storey
authors: Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland.
authors: William T A
authors: WT
authors: Harrison
keywords: Fused rings; conformation; crystal structure; intra­molecular O—H⋯O hydrogen bonds; weak inter­actions