3,4-dihydro-2H-pyran → HCID 66617162, compound

HRID 455776Notes

Reaction equation

HRID 455776 reaction equation
[O:1]1[CH:6]=[CH:5][CH2:4][CH2:3][CH2:2]1.[CH2:7]([O:9][C:10](=[O:34])[C:11]([CH3:33])([CH3:32])[CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH:17]([OH:31])[CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][C:23]([CH3:30])([CH3:29])[C:24]([O:26][CH2:27][CH3:28])=[O:25])[CH3:8].O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C(Cl)Cl>[CH2:27]([O:26][C:24](=[O:25])[C:23]([CH3:29])([CH3:30])[CH2:22][CH2:21][CH2:20][CH2:19][CH2:18][CH:17]([O:31][CH:6]1[CH2:5][CH2:4][CH2:3][CH2:2][O:1]1)[CH2:16][CH2:15][CH2:14][CH2:13][CH2:12][C:11]([CH3:33])([CH3:32])[C:10]([O:9][CH2:7][CH3:8])=[O:34])[CH3:28]

Participants

5

Reactant 3

HCID 80803,4-dihydro-2H-pyranHCID 521998p-Toluenesulfonic acid monohydrateHCID 11304147Pentadecanedioic acid, 8-hydroxy-2,2,14,14-tetramethyl-, 1,15-diethyl ester

Product 1

HCID 66617162HCID 66617162, compoundYield 62.4%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Under nitrogen atmosphere, 3,4-dihydro-2H-pyran (10.2 g, 121 mmol) was added dropwise to a stirred solution of 8-hydroxy-2,2,14,14-tetramethypentadecanedioic acid diethyl ester (16.1 g, 40 mmol) and p-toluenesulfonic acid monohydrate (catalytic amounts) in methylene chloride (100 mL) under cooling with an ice bath. The reaction mixture was allowed to warm to room temperature and stirred overnight. After the reaction was completed (TLC), the solution was filtered through basic aluminum oxide (50 g), which was washed with methylene chloride (4×30 mL). The filtrate was concentrated in vacuo to give crude product (19.5 g), which was purified by chromatography (silica gel, 200 g, heptanes/ethyl acetate=20:1, 10:1) yielding 2,2,14,14-tetramethyl-8-(tetrahydropyran-2-yloxy)-pentadecanedioic acid diethyl ester as a colorless oil (12.1 g, 62%). 1H NMR (300 MHz, CDCl3/TMS): δ (ppm): 4.69-4.59 (m, 1H), 4.11 (q, J=7.3 Hz, 4H), 3.98-3.82 (m, 1H), 3.65-3.40 (m, 2H), 2.00-1.18 (m, 26H), 1.24 (t, J=7.1 Hz, 6H), 1.15 (s, 12H). 13C NMR (75 MHz, CDCl3/TMS): δ (ppm): 177.74, 97.36, 76.48, 62.61, 60.02, 42.05, 40.70, 40.63, 34.90, 33.38, 31.16, 30.32, 30.26, 25.48, 25.10, 24.86, 19.96, 14.23.

Workup

  1. temperatureunder cooling with an ice bath
  2. filtrationthe solution was filtered through basic aluminum oxide (50 g), which
  3. washwas washed with methylene chloride (4×30 mL)
  4. concentrationThe filtrate was concentrated in vacuo
  5. customto give crude product (19.5 g), which
  6. customwas purified by chromatography (silica gel, 200 g, heptanes/ethyl acetate=20:1, 10:1)

Sources & evidence

ORD record
ord-f7498e1fc5fb492fb4edc2c35f13311d
Source dataset
uspto-grants-2013_07
Patent number
US08497301B2

Reaction notes

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