Crystal structure and absolute configuration of (3aS,4S,5R,7aR)-2,2,7-trimethyl-3a,4,5,7a-tetra-hydro-1,3-benzodioxole-4,5-diol

Enantioselective Synthesis of a New Non-Natural Gabosine

The preparation of a new non-natural gabosine is reported, in which the chirality is transferred from the toluene’s biotransformed metabolite (1R,2S)-3-methylcyclohexa-3.5-diene-1,2-diol. Further chemical transformations to introduce additional functionality and chirality to the molecule were also accomplished.

General Method for the Synthesis of (-)-Conduritol C and Analogs from Chiral Cyclohexadienediol Scaffolds

An efficient and facile general method for the synthesis of conduritol C analogs, taking advantage of an enantioselective biocatalysis process of monosubstituted benzenes, is described. The absolute stereochemical patterns of the target molecules (−)-conduritol C, (−)-bromo-conduritol C, and (−)-methyl-conduritol C were achieved by means of chemoenzymatic methods. The stereochemistry present at the homochiral cyclohexadiene-cis-1,2-diols derived from the arene biotransformation and the enantioselective ring opening of a non-isolated vinylepoxide derivative permitted the absolute configuration of the carbon bearing the hydroxyl groups at the target molecules to be established. All three conduritols and two intermediates were crystallized, and their structures were confirmed by X-ray diffraction. The three conduritols and intermediates were isostructural. The versatility of our methodology is noteworthy to expand the preparation of conduritol C analogs starting from toluene dioxygenase (TDO) monosubstituted arene substrates.

Crystal structure and absolute configuration of (3aR,3'aR,7aS,7'aS)-2,2,2',2'-tetra-methyl-3a,6,7,7a,3'a,6',7',7'a-octa-hydro-4,4'-bi[1,3-benzodioxol-yl], obtained from a Pd-catalyzed homocoupling reaction

The absolute configuration, i.e. (3aR,3'aR,7aS,7'aS), of the title compound, C18H26O4, synthesized via a palladium-catalyzed homocoupling reaction, was determined on the basis of the synthetic pathway and was confirmed by X-ray diffraction. The homocoupled mol-ecule is formed by two chemically identical moieties built up from two five- and six-membered fused rings. The supra-molecular assembly is controlled mainly by C-H⋯O inter-actions that lead to the formation of hydrogen-bonded chains of mol-ecules along the [001] direction, while weak dipolar inter-actions and van der Waals forces hold the chains together in the crystal structure.