Asymmetric synthesis of octahydrobenzofuran core structure with three contiguous stereogenic centers and development of the absolute configurations

Cyclization of enantiopure (S/R)-1 with halogen-reagent-constructed enantiopure octahydrobenzofuran core structure with contiguous three stereogenic centers of both enantiomers (SRR and RSS). The absolute configurations of all compounds have been established from X-ray analysis of the single crystal of (3aS,7aR,7R)-3. The chiral initiation in diastereoselective mode of 5-exo ring closure across CC bond of pendant cyclohexene moiety has been proposed.