反应详情

A solution of 2.0 g (4.1 mmole) of [(2R)-7-(benzyloxy)-8-(3-hydroxypropyl)-2,3-dihydro-1,4-benzodioxin-2-yl]methyl 4-methylbenzenesulfonate in 100 mL of methanol was added to a slurry of 0.30 g of 10% palladium on carbon in 30 mL of methanol in 500 mL Parr hydrogenation bottle. The mixture was treated with 50 psi of hydrogen on a Parr shaker for 15 hours. The catalyst was then removed by filtration through celite and the filtrate concentrated in vacuum to 1.6 g of a colorless oil. The oil was dissolved in 100 mL of benzene, 2.1 g (8.0 mmole) of triphenylphosphine and 1.6 g (8.0 mmole) of diisopropylazodicarboxylate added and the mixture stirred at room temperature for 5 days. The solvent was then removed in vacuum and the residue column chromatographed on silica gel with methylene chloride as eluant to give 1.2 g of the (R)-enantiomer of the title compound as a pale yellow oil. 1H-NMR (CDCl3): doublet 7.8 δ (2H); doublet 7.35 δ (2H); doublet 6.6 δ (1H); doublet 6.35 δ (1H); multiplet 4.4 δ (1H); multiplet 4.2 δ (3H); triplet 4.1 δ (2H); doublet of doublets 4.0 δ (1H); multiplet 2.55 δ (2H); singlet 2.45 δ (3H); multiplet 1.9 δ (2H).

1. customThe catalyst was then removed by filtration through celite
2. concentrationthe filtrate concentrated in vacuum to 1.6 g of a colorless oil
3. dissolutionThe oil was dissolved in 100 mL of benzene
4. customThe solvent was then removed in vacuum
5. customthe residue column chromatographed on silica gel with methylene chloride as eluant