Tetrahydrofuran → 3-(2H-pyran-4(3H,5H,6H)-ylidene)propan-1-ol

Reaktionsgleichung

[PH4+].[Li]CCCC.[O:7]1[CH2:12][CH2:11][C:10](=O)[CH2:9][CH2:8]1.[CH2:14]1C[O:17][CH2:16][CH2:15]1>>[O:7]1[CH2:12][CH2:11][C:10](=[CH:14][CH2:15][CH2:16][OH:17])[CH2:9][CH2:8]1

Komponenten

Edukt 4

HCID 8028Tetrahydrofuran

HCID 121599Tetrahydro-4H-pyran-4-one

HCID 5460504Phosphonium

HCID 178418339Butyllithium

Produkt 1

HCID 574196163-(2H-pyran-4(3H,5H,6H)-ylidene)propan-1-olAusbeute 61 %

Versuchsvorschrift

To a suspension of the phosphonium salt (90.2 g, 1.5 eq) in dry THF (1100 mL) at 0° C. under nitrogen atmosphere was added n-BuLi (2.5 M, 216 mL, 0.54 mol). The solution was stirred for 1 h, followed by addition of dihydro-2H-pyran-4(3H)-one (15 g, 0.15 mol). Stirring was continued at rt overnight. The mixture was quenched with satd aq NH4Cl, and then filtered. The filtrate was dried over Na2SO4, and concentrated under vacuum to give the crude product, which was purified by column chromatography to give the product (13.1 g, 61%). 1H NMR (CD3OD) δ 2.1-2.3 (m, 6H), 2.5 (s, 1H), 3.5-3.7 (m, 6H), 5.1-5.2 (t, 1H).