Dimethyl (3,3-difluoro-2-oxoheptyl)phosphonate → (3aR,4R,5R,6aS)-4-((E)-4,4-difluoro-3-oxo-1-octenyI)-2-oxo-5-(phenylmethoxy)hexahydro-2H-cyclopenta[b]furan

Participants

Reaction Steps

To a mixture of dimethyl(3,3-difluoro-2-oxoheptyl)phosphonate (210 mg, 0.81 mmoL) in MTBE/H2O (3/0.1 mL) was added Zn(OH)2 (100 mg, 0.81 mmoL) and the mixture was stirred under nitrogen for 1 h. A solution of (3aR,4R,5R,6aS)-hexahydro-2-oxo-5-(phenylmethoxy)-2H-cyclopenta[b]furan-4-carboxaldehyde (200 mg, 0.77 mmoL) in dichloromethane (3 mL) was added and the mixture was stirred for 24 h. After completion of the reaction, the reaction was then quenched with cold 1N HCl (12 mL). The organic layer was separated, washed with brine, dried over Na2SO4 and concentrated to dryness under vacuum. The crude material was further purified by column chromatography [25% ethyl acetate in heptanes] to yield (3aR,4R,5R,6aS)-4-((E)-4,4-difluoro-3-oxo-1-octenyl)-2-oxo-5-(phenylmethoxy)hexahydro-2H-cyclopenta[b]furan (7, R1 is phenyl, and R2 and R3 are H) in 76% yield.

Provenance & Evidence