(S)-2'-amino-3-(3,6-dihydro-2H-pyran-4-yl)-5'H-spiro[chromeno[2,3-b]pyridine-5,4'-oxazol]-7-ol → (S)-2'-amino-3-(tetrahydro-2H-pyran-4-yl)-5'H-spiro[chromeno[2,3-b]pyridine-5,4'-oxazol]-7-ol

Participants

Reaction Steps

A 25-mL flask was charged with (S)-2′-amino-3-(3,6-dihydro-2H-pyran-4-yl)-5′H-spiro[chromeno[2,3-b]pyridine-5,4′-oxazol]-7-ol (211 mg, 0.601 mmol) and MeOH (75070 μL). The mixture was sonicated for 1 min to give an opaque mixture. Palladium on carbon (63.9 mg, 0.060 mmol) was added, and H2 (g) was bubbled through the mixture for 1 min. The mixture was stirred further under a balloon of H2 (g) for 60 hours. The mixture was filtered through celite with the aid of methanol. The filtrate was evaporated, and the residue was chromatographed on a 40-g Redi-Sep column with 0-100% of a 90:10:1 mix of DCM/MeOH/NH4OH to give (S)-2′-amino-3-(tetrahydro-2H-pyran-4-yl)-5′H-spiro[chromeno[2,3-b]pyridine-5,4′-oxazol]-7-ol as an off-white solid.

Provenance & Evidence