Nitroxyl Radical/PhI(OAc)₂: One-Pot Oxidative Cleavage of Vicinal Diols to (Di)Carboxylic Acids

A mild and user-friendly one-pot oxidative cleavage of vicinal diols to their corresponding (di)carboxylic acids using AZADOs and PhI(OAc)₂ is described. 1,2-Diols and 2,3-diols as well as 1,2,3-triol gave one- or two-carbon-unit-shorter carboxylic acids. Internal vicinal diols also smoothly underwent one-pot oxidative cleavage to afford the corresponding dicarboxylic acids. Cyclic vicinal diols are converted to their corresponding open-form dicarboxylic acids

Organocatalytic One-Pot Oxidative Cleavage of Terminal Diols to Dehomologated Carboxylic Acids

The organocatalytic one-pot oxidative cleavage of terminal 1,2-diols to one-carbon-unit-shorter carboxylic acids is described. The combination of 1-Me-AZADO (cat.), NaOCl (cat.), and NaClO₂ caused smooth one-pot oxidative cleavage under mild conditions. A broad range of substrates including carbohydrates and <i>N</i>-protected amino diols were converted without epimerization. Terminal triols and tetraols respectively underwent cleavage of their C-2 and C-3 moieties to afford their corresponding two- and three-carbon-unit-shorter carboxylic acids

Nazarov Cyclization Entry to Chiral Bicyclo­[5.3.0]­decanoid Building Blocks and Its Application to Formal Synthesis of (−)-Englerin A

A divergent entry to the chiral bicyclo[5.3.0]­decane skeletons relevant to sesqui- and higher terpenoids has been achieved. Its usefulness was demonstrated by formal synthesis of a guaiane sesquiterpenoid (−)-englerin A. The key reactions are (i) diastereoselective Nazarov cyclization for stereoselective construction of the bicyclo[5.3.0]­decane skeleton, (ii) intramolecular C–H amination for tuning an oxidation state, and (iii) introduction of an alkyl group to a β-alkoxy ketone with a zinc­(II) ate complex