No abstract

The reaction of a series of ketones with dimsylsodium in dimethyl sulfoxide resulting in the formation of gamma-unsaturated thiols was studied experimentally. [2,3]-Sigmatropic rearrangements of beta-unsaturated sulfinyl carbanions are involved at the key step of those transformations. DFT computations at the B3LYP/6-31+G level indicated that such rearrangements, as well as some typical [2, 3]-sigmatropic rearrangements, e.g., thermal rearrangements of allyl sulfoxides and Wittig rearrangements of sulfur ylides and lithiated allyloxy methyl anions, are concerted and moderately synchronous processes. Negative (diatropic) nucleus-independent chemical shifts (NICS) and high diamagnetic susceptibility exaltations indicate that the transition structures of these [2,3]-sigmatropic migrations are aromatic.

No abstract

The reaction of 1-hydroxydiamantane with elemental bromine leads to consecutive cage opening and re-closure, thereby providing a straightforward approach to the class of previously unknown 1,2disubstituted diamondoid derivatives. Functional group exchange gave, among others, chiral bidentate ligands 1,2-dihydroxy-and 1,2-diaminodiamantane. The latter was enantioseparated on gram scale with ee >98% through a single crystallization with (+)-tartaric acid.