Methyl acetoacetate → 5-(3,6-dihydro-4-hydroxy-6-oxo-2-phenyl-2H-pyran-2-yl)pentanoic acid

HRID 357833Notes

Reaction equation

HRID 357833 reaction equation
[C:1](OC)(=[O:6])[CH2:2][C:3]([CH3:5])=[O:4].[H-].[Na+:10].C([Li])CCC.[Na+].[C:17]([CH2:25][CH2:26][CH2:27][CH2:28][C:29]([O-:31])=[O:30])(=[O:24])[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1>CCCCCC.O1CCCC1>[OH:4][C:3]1[CH2:5][C:17]([CH2:25][CH2:26][CH2:27][CH2:28][C:29]([OH:31])=[O:30])([C:18]2[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=2)[O:24][C:1](=[O:6])[CH:2]=1.[Na+:10].[C:17]([CH2:25][CH2:26][CH2:27][CH2:28][C:29]([O-:31])=[O:30])(=[O:24])[C:18]1[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1

Participants

8

Reactant 4

HCID 7757Methyl acetoacetateHCID 24758Sodium hydride2×HCID 698361915-Benzoylpentanoic acid sodium saltHCID 178418339Butyllithium

Product 2

HCID 546766295-(3,6-dihydro-4-hydroxy-6-oxo-2-phenyl-2H-pyran-2-yl)pentanoic acidHCID 698361915-Benzoylpentanoic acid sodium salt

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent3×HCID 8058HexaneSolvent2×

Procedure

The title compound was prepared as described in General Method 1 using 25 mmol of methyl acetoacetate, 27.5 mmol of NaH 60% dispersion in oil, 26.25 mmol of 1.6M n-butyl lithium in hexane in 50 mL of tetrahydrofuran and 25 mmol of 5-benzoylpentanoic acid sodium salt in 100 mL of tetrahydrofuran. 5-Benzoylpentanoic acid sodium salt was prepared by reacting the acid (25 mmol) with hexane washed NaH (27.5 mmol) in tetrahydrofuran at 0° C. for 25 minutes. The crude solid was recrystallized from ethyl acetate (m.p. 136°-140° C.). 1H NMR (DMSO-d6) δ 0.8-1.0 (m, 1 H), 1.1-1.3 (m, 1 H), 1.3-1.5 (m, 2 H), 1.8-2.0 (m, 2 H), 2.1 (t, 2 H), 2.9 (ABq, 2 H), 4.85 (s, 1 H), 7.2-7.4 (m, 5 H), 11.4 (bs, 1 H), 12.0 (bs, 1 H).

Workup

  1. customThe crude solid was recrystallized from ethyl acetate (m.p. 136°-140° C.)

Sources & evidence

ORD record
ord-cfa8f94b45d34acc9d3ef74c38b40168
Source dataset
uspto-grants-1998_11
Patent number
US05840751

Reaction notes

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