[reaction: see text] The tethered aminohydroxylation (TA) of acyclic allylic carbamates has been achieved in a stereospecific and stereoselective manner. Unusually high levels of stereocontrol were observed in the oxidation of 1,1-disubstituted substrates.

Studies towards the biomimetic synthesis of mycaperoxide B (1) are described. We have established the synthesis of four diastereoisomers of mycaperoxide B methyl ester (1a) by employing a Michael addition across an α,β-unsaturated ester precursor 2 as the key step. This result strongly suggests stereocontrol in the addition of the hydroperoxide function-

Since Sharpless' discovery of the asymmetric aminohydroxylation (AA) reaction, a major challenge for chemists has been to find ways of controlling the regio- and stereochemical outcome of this important reaction. Detailed herein is a review of our novel approach towards gaining reliable and predictable regio- and stereocontrol through the use of a tethered carbamate to promote an intramolecular AA reaction, along with a description of the mechanism proposed for this new methodology.

[reaction: see text] Stereoselective aminohydroxylation and dihydroxylation using osmium(VIII) oxidants enabled the short and efficient synthesis of the aminocyclitol core of hygromycin A. In addition to allowing the selective introduction of the heteroatoms N and O, the use of osmium (via an osmate ester) as a protecting group for a 1,2-glycol is also reported. This tactic allowed efficient differentiation of otherwise equivalent hydroxyl groups and allowed us to complete the synthesis in short order (14 steps) and excellent overall yield (12%).