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

Abstract

Amino deoxysugars are abundant in nature and play an important role in various biological functions, promoting numerous efforts to synthesize their structurally unique motifs. In this report, a de novo approach from a readily available lactic acid derivative is devised to construct several amino deoxysugars embedded in natural products, featuring a novel nitroso-ene-type cyclization to introduce a nitrogen atom into the carbon framework. This efficient synthesis provides an unprecedented synthetic route to explore the nitroso-ene cyclization to accumulate intriguing amino deoxysugars.

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

“…The NO bond exhibits a marked similarity to polarized carbon–carbon and carbon–heteroatom π bonds. This resemblance has prompted the development of nitroso versions of some common organic reactions, including the nitroso-aldol reaction, nitroso-Diels–Alder reaction, nitroso-ene reaction, nitroso-Cope rearrangement, nitroso-Povarov reaction, and others (Scheme A–E). Here we report on a spontaneous intramolecular nitroso-Meerwein–Ponndorf–Verley–Oppenauer reaction that was serendipitously discovered in our studies on the synthesis of δ-hydroxy gem -chloronitroso compounds 2 from 1,2-oxazine N -oxides 1 (Scheme , F).…”

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

“…In the context of synthetic design, the α-quaternary amino acid in sphingolipids has attracted significant interest for both method development and synthetic strategies. , In our ongoing exploration of the reactivity of nitroso species toward structural variants of bioactive molecules, − we envisioned a novel strategy to achieve the C–N bond formation through a nitroso–ene (NE) reaction of the conjugated ester. The nitroso–ene reaction has emerged as an appealing method to prepare allylic amines 2 (Scheme A) .…”