Nitroso-Ene-type Cyclization Toward Diversified Synthesis of Amino Deoxysugars: A Proof of Concept

An Intramolecular Nitroso-Meerwein-Ponndorf-Verley-Oppenauer Reaction to Access Fused Pyrrolidine Scaffolds

δ-Hydroxy chloronitroso compounds generated in situ from 1,2-oxazine N-oxides undergo a 1,5-hydride transfer related to the Meerwein-Ponndorf-Verley-Oppenauer reaction. Based on the process discovered, a three-step access to fused pyrrolidine scaffolds containing up to four contiguous stereogenic centers starting from simple nitrostyrenes and cycloalkenes or cyclodienes has been developed. The suggested reaction mechanism was confirmed by in situ UV-vis and ATR FT-IR monitoring and DFT calculations.

All-in-One Synthesis of 3,6-Dideoxysugars: An Olefin Metathesis-Isomerization Approach

A collective synthesis of 3,6-dideoxysugars, including seven naturally known congeners, has been reported using commercially available methyl lactates in five steps. The essential tandem process involving the olefin cross-metathesis and isomerization steps was enabled by the dual function of Grubbs-II catalyst, affording the products in good yields and providing concise and practical access to a class of biologically important deoxysugars.

Total Synthesis of Immunosuppressive Mycestericin E and G Enabled by a Highly Stereoselective Nitroso-Ene Cyclization

This report describes a streamlined synthesis of immunosuppressive mycestericin E and G through a highly stereoselective nitroso-ene cyclization in 11-12 steps using readily available materials. The stereochemical outcome in the formation of a Nα-quaternary stereogenic center is rationalized by a trajectory based on the polar diradical intermediate and subsequent hydrogen transfer. Julia olefination offers a facile chain elongation method that presents a viable strategy for structural derivatization in future medicinal applications.