Triphenylphosphine → 2,3,9,10-Tetrahydro-8H-[1,4]dioxino[2,3-f]chromen-2-ylmethyl 4-methylbenzenesulfonate

HRID 49257Notes

Reaction equation

HRID 49257 reaction equation
[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([S:8]([O:11][CH2:12][C@@H:13]2[O:18][C:17]3[C:19](CCCO)=[C:20]([O:23][CH2:24][C:25]4C=CC=C[CH:26]=4)[CH:21]=[CH:22][C:16]=3[O:15][CH2:14]2)(=[O:10])=[O:9])=[CH:4][CH:3]=1.[H][H].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.CC(OC(/N=N/C(OC(C)C)=O)=O)C>CO.[Pd]>[CH3:1][C:2]1[CH:7]=[CH:6][C:5]([S:8]([O:11][CH2:12][CH:13]2[O:18][C:17]3=[C:19]4[C:20](=[CH:21][CH:22]=[C:16]3[O:15][CH2:14]2)[O:23][CH2:24][CH2:25][CH2:26]4)(=[O:10])=[O:9])=[CH:4][CH:3]=1

Participants

7

Reactant 4

HCID 11776TriphenylphosphineHCID 5363146Diisopropyl azodicarboxylateHCID 86586536[(2R)-7-(benzyloxy)-8-(3-hydroxypropyl)-2,3-dihydro-1,4-benzodioxin-2-yl]methyl 4-methylbenzenesulfonateHCID 178418361HCID 178418361, compound

Product 1

HCID 185460132,3,9,10-Tetrahydro-8H-[1,4]dioxino[2,3-f]chromen-2-ylmethyl 4-methylbenzenesulfonate

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 887MethanolSolvent2×

Procedure

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 (2H); doublet of doublets 4.0 δ (1H); multiplet 2.55 δ (2H); singlet 2.45 δ (3H); multiplet 1.9 δ (2H).

Workup

  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

Sources & evidence

ORD record
ord-74dc9b1d2b28475baa9a3f14393a053d
Source dataset
uspto-grants-2004_03
Patent number
US06706736B2

Reaction notes

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