3,4-dihydro-2H-pyran → HCID 12070866, compound

HRID 2393571Notes

Reaction equation

HRID 2393571 reaction equation
[CH:1]1([C@H:7]([OH:20])[CH2:8][CH2:9][C@@H:10]2[C@@H:17]3[C@@H:13]([O:14][C:15](=[O:18])[CH2:16]3)[CH2:12][C@H:11]2[OH:19])[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1.[O:21]1[CH:26]=[CH:25][CH2:24][CH2:23][CH2:22]1>C(Cl)Cl.CC1C=CC(S(O)(=O)=O)=CC=1>[CH:1]1([C@H:7]([O:20][CH:22]2[CH2:23][CH2:24][CH2:25][CH2:26][O:21]2)[CH2:8][CH2:9][C@@H:10]2[C@@H:17]3[C@@H:13]([O:14][C:15](=[O:18])[CH2:16]3)[CH2:12][C@H:11]2[O:19][CH:26]2[CH2:25][CH2:24][CH2:23][CH2:22][O:21]2)[CH2:6][CH2:5][CH2:4][CH2:3][CH2:2]1

Participants

5

Reactant 2

HCID 80803,4-dihydro-2H-pyranHCID 12070865HCID 12070865, compound

Product 1

HCID 12070866HCID 12070866, compoundYield 89.9%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

A solution of the diol 7 (6.0 g, 21.2 mmol) and dihydropyran (7.80 mL, 84.8 mmol) in CH2Cl2 (100 mL) was cooled to 0° C. A catalytic amount of p-TsOH (0.05 g, 0.26 mmol) was added and the mixture was stirred for 30 min at 0° C. The reaction was then quenched by adding sat. aqueous NaHCO3 (10 mL). Layers were separated and the aqueous phase was extracted with 2×25 mL of CH2Cl2. Combined organic layers were dried over anhydrous K2CO3, filtered and concentrated to afford a colorless oil which was purified by passage through a short column of silica (Rf =0.46, 1:1 EtOAc/hexanes). The bis-THP ether 8 (8.59 g, 89% yield) was isolated as a colorless oil which solidified upon standing. 1H NMR (CDCl3) δ (characteristic peaks only) 5.00 (m, 1H), 4.75-4.45 (m, 2H), 3.85 (m, 2H), 3.60-3.30 (m, 4H).

Workup

  1. customThe reaction was then quenched
  2. additionby adding sat. aqueous NaHCO3 (10 mL)
  3. customLayers were separated
  4. extractionthe aqueous phase was extracted with 2×25 mL of CH2Cl2
  5. dry with materialCombined organic layers were dried over anhydrous K2CO3
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customto afford a colorless oil which
  9. customwas purified by passage through a short column of silica (Rf =0.46, 1:1 EtOAc/hexanes)

Sources & evidence

ORD record
ord-a38174cd75b8417ba151e4b95a850166
Source dataset
uspto-grants-1998_09
Patent number
US05807892

Reaction notes

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