Abstract
An atom-economic and diazo-free strategy for the construction of novel pseudo anomeric C-1 alkenyl spirocyclopropyl sugars is described. Leveraging the 1,2-migration pathway of propargyl esters under gold(I) catalysis, easily available exo-glycals undergo β-selective alkenylcarbenoid insertion in moderate to excellent yields. Preferential activation of propargyl moieties and concerted [2 + 1] insertion are both favored through ligand choice and electron enrichment of esters. Stereocontrol using conformational bias and rearrangement are also demonstrated.
Graphical Abstract


![[Translate to English:]](/websites/_processed_/0/4/csm_signature-unistra_16a9ad672e.png)
![[Translate to English:]](/websites/_processed_/0/e/csm_logo-cnrs_c35686510a.png)
![[Translate to English:]](/websites/_processed_/9/4/csm_logo-fondation-lehn_e04fdb6c72.png)