2,3-dihydro-7-hydroxy-8-pentyl-4H-1-benzopyran-4-one → 2-[5-[(3,4-dihydro-4-oxo-8-pentyl-2H-1-benzopyran-7-yl)oxy]pentyloxy]benzenepropanoic acid methyl ester
Reaction equation
[OH:1][C:2]1[CH:12]=[CH:11][C:5]2[C:6](=[O:10])[CH2:7][CH2:8][O:9][C:4]=2[C:3]=1[CH2:13][CH2:14][CH2:15][CH2:16][CH3:17].[CH3:18][O:19][C:20](=[O:40])[CH2:21][CH2:22][C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][C:24]=1[O:29][CH2:30][CH2:31][CH2:32][CH2:33][CH2:34]OS(C)(=O)=O>>[CH3:18][O:19][C:20](=[O:40])[CH2:21][CH2:22][C:23]1[CH:28]=[CH:27][CH:26]=[CH:25][C:24]=1[O:29][CH2:30][CH2:31][CH2:32][CH2:33][CH2:34][O:1][C:2]1[CH:12]=[CH:11][C:5]2[C:6](=[O:10])[CH2:7][CH2:8][O:9][C:4]=2[C:3]=1[CH2:13][CH2:14][CH2:15][CH2:16][CH3:17]Participants
Procedure
Using the procedure of example 11 and starting with 1.25 g (5.34 mmol) of 2,3-dihydro-7-hydroxy-8-pentyl-4H-1-benzopyran-4-one (from example 117) and 1.64 g (4.76 mmol) of 2-[[5-[(methylsulfonyl)oxy]pentyl]oxy]benzenepropanoic acid methyl ester (from example 72), 2-[5-[(3,4-dihydro-4-oxo-8-pentyl-2H-1-benzopyran-7-yl)oxy]pentyloxy]benzenepropanoic acid methyl ester was obtained in 98% yield (2.52 g) as a pale-yellow oil. This diester (5.18 mmol) was saponified with 7.8 mL of 3N aqueous lithium hydroxide in 25 mL of tetrahydrofuran, at room temperature, for 48 hr. Work-up as in example 4 gave 2-[5-[(3,4-dihydro-4-oxo-8-pentyl-2H-1-benzopyran-7-yl)oxy]pentyloxy]benzenepropanoic acid as an oil. This material was flash chromatographed on silica gel eluting with ethyl acetate-hexane mixtures giving 0.69 g (28.5%) of pure acid as a solid. Recrystallization from acetonitrile gave a colorless solid, mp 86°-87° C.
Sources & evidence
- ORD record
- ord-44610232e7de42778e3108077a1dff8b
- Source dataset
- uspto-grants-1995_07
- Patent number
- US05434186
Reaction notes
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