Methyl acetoacetate → 5,6-Dihydro-4-hydroxy-6-phenyl-6-propyl-2H-pyran-2-one

HRID 481851

Reaction equation

[C:1]([O:7][CH3:8])(=[O:6])[CH2:2][C:3]([CH3:5])=[O:4].[H-].[Na+].[CH2:11]([Li])[CH2:12][CH2:13]C.C([C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)(=O)CCC.[NH4+].[Cl-]>CCCCCC.O1CCCC1>[OH:4][C:3]1[CH2:5][C:8]([C:21]2[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=2)([CH2:11][CH2:12][CH3:13])[O:7][C:1](=[O:6])[CH:2]=1

Participants

Conditions

Temperature: 0 °C

Procedure

The title compound was prepared as described in the General Method 1 using 5 mmol of methyl acetoacetate, 5.5 mmol of NaH 60% dispersion in oil, 5.5 mmol of 1.6M n-butyl lithium in hexane, 5.5 mmol of butyrophenone and 14 mL of tetrahydrofuran. After addition of the ketone, the reaction was stirred for 90 minutes at 0° C. The reaction was poured into saturated NH4Cl solution and extracted with ethyl acetate. The organic layer was dried over MgSO4, concentrated, and the residue flash chromatographed using hexane/ethyl acetate 80/20 as eluent. The aldol product was stirred at room temperature in 100 mL of 0.1N NaOH for 3.5 hours. The reaction was worked up as in General Method 1 and the product triturated from diethyl ether to afford a solid (m.p. 131.5°-132° C.). 1H NMR (CDCl3) δ0.88 (t, 3H), 1.1-1.4 (m, 2H), 1.95 (m, 2H), 2.90 (d, 1H), 2.92 (d, 1H), 3.25 (d, 1H), 3.35 (d, 1H), 7.2-7.4 (m, 5H).

Workup

extractionextracted with ethyl acetate
dry with materialThe organic layer was dried over MgSO4
concentrationconcentrated
customthe residue flash chromatographed
stirringThe aldol product was stirred at room temperature in 100 mL of 0.1N NaOH for 3.5 hours
customthe product triturated from diethyl ether

Sources & evidence

ORD record: ord-adb45a93712b42b5979aca8328a8e04b
Source dataset: uspto-grants-1998_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05789440

Linked notes

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