A versatile approach toward enantiospecific synthesis of sugar-linked oxapolyquinanes <i>via</i> IPKR

An efficient and enantiospecific synthetic strategy for the construction of [6/5/5/5] and [5/5/5/5] fused oxatetraquinanes using a D-glucose-derived enyne has been described. The approach integrates oxidative cleavage, organoaluminium-mediated propargylation, and IPKR (Intramolecular Pauson-Khand Reaction) to deliver the tetracyclic core with high stereoselectivity. These tetracyclic cores serve as versatile synthons for the synthesis of more complex [6/5/5/5/5] fused polyquinanes. This methodology not only highlights the strategic use of carbohydrate-derived enynes but also provides a robust platform for the asymmetric synthesis of structurally intricate polyquinanes, paving the way for the development of biologically relevant molecular frameworks.