LAUSR

An indolizidine alkaloid, (‐)‐8a‐epi‐lentiginosine was synthesized from d‐glucose using the Pd‐BiPhePhos catalyzed intramolecular Tsuji‐Trost reaction of non‐derivatized allylic alcohol as a key construction of the hydroxylated pyrrolidine ring to give the desired product in good yield and high diasterespecificity stereospecificity (dr = 97:3).  The absolute configuration and structure of the (‐)‐8a‐epi‐lentiginosine were confirmed by NMR and X‐ray crystal structure analysis. The crystal structure of (‐)‐8a‐epi‐lentiginosne showed the envelope conformation of the five‐membered ring which is an N‐atom in the endo‐position and the fused six‐membered ring adopts a chair conformation similar to the DFT optimized structure. The solid‐state packing is dominated by a 1D‐hydrogen bonded network along the a‐axis involving both hydroxyl groups and the amine. The large HOMO‐LUMO energy gap indicated the high stability of the compound.