Tetrahydro-2-(2-propynyloxy)-2H-pyran → 4-Hydroxy-4-[3-(tetrahydropyran-2-yloxy)prop-1-ynyl]tetrahydropyran

HRID 21898

Reaction equation

[CH2:1]([O:4][CH:5]1[CH2:10][CH2:9][CH2:8][CH2:7][O:6]1)[C:2]#[CH:3].C([Mg]Br)C.[O:15]1[CH2:20][CH2:19][C:18](=[O:21])[CH2:17][CH2:16]1>C1COCC1>[OH:21][C:18]1([C:3]#[C:2][CH2:1][O:4][CH:5]2[CH2:10][CH2:9][CH2:8][CH2:7][O:6]2)[CH2:19][CH2:20][O:15][CH2:16][CH2:17]1

Participants

Conditions

Temperature: -20 °C

Procedure

Tetrahydro-2-(2-propynyloxy)-2H-pyran (21 g, 150 mmol) was converted to the corresponding magnesium anion by deprotonation with ethyl magnesium bromide (75 mL of a 2M solution, 150 mmol) according to the method described in Org. Synth., 60: 81, 7 (1981). The resulting anion was cooled to -20° C. and tetrahydro-4H-pyran-4-one (14.8 g, 148 mmol) in dry THF (30 mL) was added dropwise and the resulting solution stirred for three hours. The reaction was quenched by addition of crushed ice and saturated aqueous NH4Cl. The resulting two-layered mixture was extracted with ether (3×150 mL). The combined organic layers were dried over MgSO4, filtered, and concentrated in vacuo. Purification by chromatography on silica gel (200 g, 20% ethyl acetate: hexanes) provided 4-hydroxy-4-[3-(tetrahydropyran-2-yloxy)prop-1-ynyl]tetrahydropyran(31.4 g, 88%).

Workup

customThe reaction was quenched by addition of crushed ice and saturated aqueous NH4Cl
extractionThe resulting two-layered mixture was extracted with ether (3×150 mL)
dry with materialThe combined organic layers were dried over MgSO4
filtrationfiltered
concentrationconcentrated in vacuo
customPurification by chromatography on silica gel (200 g, 20% ethyl acetate: hexanes)

Sources & evidence

ORD record: ord-fc58a5611d344ef8933ea94ade1a5a7d
Source dataset: uspto-grants-1995_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05426111

Linked notes

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