Packing in three cyclooctitol acetates.

Three cyclooctitol derivatives, in the form of a tetraacetate, (1S*,2R*,3S*,4S*)-2,3,4-triacetoxycyclooctan-1-ylmethyl acetate, C17H26O8, and two regioisomeric acetonide triacetates, (3aS*,4R*,8S*,9S*,9aS*)-8,9-diacetoxy-2,2-dimethylcyclooctano[d][1,3]dioxan-4-ymethyl acetate and (3aS,4R,7S,9R,9aS)-7,9-diacetoxy-2,2-dimethylcyclooctano[d][1,3]dioxan-4-ylmethyl acetate, both C18H28O8, have been studied. The conformation of the cyclooctane ring in the three compounds is quite close to the boat-chair form of the parent hydrocarbon. Packing is effected through weak C-H...O and van der Waals contacts.

A total synthesis of guanacastepene C.

A total synthesis of the structure corresponding to the novel tricyclic diterpene guanacastepene C has been realized in which a Knoevenagel cyclization serves as a key step to annulate the six-membered C-ring on a stereochemically secured bicyclic hydroazulene precursor.

From hydrocarbons to polyols. Cyclooctatetraene to novel cyclooctitols.

Cyclooctatetraene (COT) derived bicyclo[4.2.1]nona-2,4,7-trien-9-one has been recognized as a cyclooctane carbasugar equivalent and elaborated to a range of cyclooctane polyols (cyclooctitols) through a flexible strategy with moderate regio- and stereo-control.