The first asymmetric synthesis of (2S,3S,4R)-3-amino-2-hydroxymethyl-4-hydroxypyrrolidine

Syntheses of carbocyclic aminonucleosides and (-)-epi-4'-carbocyclic puromycin: Application of palladium(0)/indium iodide-allylations and tethered aminohydroxylations

Carbocyclic aminonucleosides and epi-4'-carbocyclic puromycin were prepared from an acylnitroso-derived hetero Diels-Alder cycloadduct. Pd(0)/InI-mediated allylations of a formyl species were used to install the 4'-hydroxymethyl group. A tethered aminohydroxylation strategy was employed to install the cis-2',3'-aminoalcohol moiety with complete regio- and diastereocontrol.

[2,3]-Sigmatropic rearrangements of 3-sulfinyl dihydropyrans: application to the syntheses of the cores of ent-dysiherbaine and deoxymalayamicin A

The [2,3]-sigmatropic rearrangement of a variety of configurationally stable diastereomeric allylic sulfinyl dihydropyrans, produced by base-promoted cyclization of sulfinyl dienols, has been studied. In some cases, the efficient transformation of these substrates into dihydropyranols required an in-depth study of reaction conditions, with the preferred protocol relying on the use of DABCO in warm toluene. This methodology has been applied to the syntheses of the cores of ent-dysiherbaine and deoxymalayamicin A by means of efficient tethered aminohydroxylations.

Synthesis of the dysiherbaine tetrahydropyran core employing a tethered aminohydroxylation reaction

A stereocontrolled and scalable synthesis of an advanced intermediate of the dysiherbaine tetrahydropyran core has been achieved in 11 steps and 27% overall yield. The key feature of this synthetic approach is the application of the Donohoe tethered aminohydroxylation reaction to install the amino diol and establish the four contiguous syn stereocenters on the tetrahydropyran ring.

N-Sulfonyloxy Carbamates as Reoxidants for the Tethered Aminohydroxylation Reaction

The use of N-sulfonyloxy carbamates as reoxidants for the tethered aminohydroxylation (TA) reaction is reported. These new conditions obviate the requirement for lithium hydroxide and tBuOCl in the oxidation mixture. In addition to providing aminohydroxylation products in good yields, the catalyst loadings can be reduced to just 1 mol % osmium. Moreover, for the first time, homoallylic alcohols are now viable substrates for the TA reaction.