HCID 54456902, compound → HCID 53743378, compound

Participants

Reaction Steps

(1 -2)A 2.04 g of benzyl (2R,3R)-3-cyclopropyl-2,3-epoxypropionate is dissolved in 40 ml of tetrahydrofuran and subjected to catalytic hydrogenation at room temperature under atmospheric pressure using 1 g of 10% palladium-carbon. After 2 hours, the catalyst is removed by filtration. After 40 ml of toluene is added to the filtrate, the resulting mixture is concentrated under reduced pressure to remove tetrahydrofuran to give a solution of (2R,3R)-3-cyclopropyl-2,3-epoxypropionic acid in toluene. Then, 2.74 g of 4α-acetoxy-2α-benzoyloxy-5β,20-epoxy-1β,13α-dihydroxy-7β,10 β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one, 1.89 g of 1,3-dicyclohexylcarbodiimide and 187 mg of 4-dimethylaminopyridine are added to the resulting solution of (2R,3R)-3-cyclopropyl-2,3-epoxypropionic acid in toluene. The mixture is stirred at 80° C. for one hour. The reaction mixture is cooled to room temperature and treated in the same manner as described in Example 4(1-1). The residue is purified by silica gel frash column chromatography (solvent; ethyl acetate:hexane=1:2) to give 3.02 g of 4α-acetoxy-2 α-benzoyloxy-13α-[(2R,3R)-3-cyclopropyl-2,3-epoxypropionyloxy]-5β,20-epoxy-1 β-hydroxy-7β,10β-bis(2,2,2-trichloroethoxycarbonyloxy)tax-11-en-9-one. The physical properties of the product are the same as those of the compound of Example 4(1-1).

Provenance & Evidence