138946-56-2

Upstream product

• 138946-45-9 5-bromo-2,3-O-isopropylidene-2,3,4-trihydroxypentanal-O-benzyl oxime 
• 138946-44-8 (3R,4S,5S)-5-(bromomethyl)-3,4-O-isopropylidenetetrahydrofuran-2,3,4-triol 
• 2687-43-6 O-benzylhydoxylamine hydrochloride 
• 138946-47-1 (4S,5S)-5-[(S)-2-Bromo-1-(tert-butyl-dimethyl-silanyloxy)-ethyl]-2,2-dimethyl-[1,3]dioxolane-4-carbaldehyde O-benzyl-oxime 

Relevant academic research and scientific papers

Synthesis of aminocyclitols by intramolecular reductive coupling of carbohydrate derived δ- and ε-functionalized oxime ethers promoted by tributyltin hydride or samarium diiodide

The intramolecular reductive coupling of a series of simple or polyoxygenated oxime ethers δ- or ε-functionalized with bromide, α,β- unsaturated ester, aldehyde, or ketone groups is reported. The cyclization of a nitrile-tethered aldehyde is also studied. These reductive couplings are promoted by tributyltin hydride or samarium diiodide. The reactions proceed under mild conditions, in good chemical yield, and with high stereoselectivity. When applied to highly functionalized substrates derived from carbohydrates, this approach provides a selective entry to enantiomerically pure aminocyclitols of varying regio- and stereochemistry. In particular, the reductive coupling reaction of carbonyl-tethered oxime ethers promoted by samarium diiodide can be performed in a one-pot sequence, following a Swern oxidation step, allowing the direct transformation of hydroxyl-tethered oxime ethers into the corresponding aminocyclitols. Moreover, the resultant O-benzylhydroxylamine products of these cyclizations can be further reduced in situ with excess samarium diiodide, in the presence of water, to the corresponding amino alcohols in excellent yields. Some transformations of these compounds are discussed.

Carbocycles from Carbohydrates. A Free Radical Route to (1R,2R,3S,4R)-4-Amino-1,2,3-cyclopentanetriol Derivatives

Some derivatives of (1R,2R,3S,4R)-4-amino-1,2,3-cyclopentanetriol have been synthesized in enantiomerically pure form via free radical cyclization of conveniently functionalized carbohydrate intermediates.Moderate yields and good to excellent diastereosel