Precocene I → 7-Methoxy-2,2-dimethyl-chroman

HRID 856942Notes

Reaction equation

HRID 856942 reaction equation
[CH3:1][C:2]1([CH3:14])[O:7][C:6]2[CH:8]=[C:9]([O:12][CH3:13])[CH:10]=[CH:11][C:5]=2[CH:4]=[CH:3]1>CCO.[Pd]>[CH3:13][O:12][C:9]1[CH:8]=[C:6]2[C:5]([CH2:4][CH2:3][C:2]([CH3:14])([CH3:1])[O:7]2)=[CH:11][CH:10]=1

Participants

4

Reactant 1

HCID 28619Precocene I

Product 1

HCID 108563167-Methoxy-2,2-dimethyl-chromanYield 90%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Procedure

A solution of precocene I (5.0 g, 26.3 mmol) in EtOH (200 mL) was hydrogenated by using 10% Pd/C (0.5 g) as catalyst. The catalyst was filtered of and EtOH was removed under reduced pressure. The crude material was then washed with dichloromethane (2×50 mL) to afford the desired product as white solid (4.55 g, 90%). 1H-NMR (CD3CN) δ 6.97 (d, J=8.0 Hz, 1H), 6.42 (d, J=8.0 Hz, 1H), 6.27 (s, 1H), 3.74 (s, 3 H), 2.72 (t, 2 H), 1.80 (t, 2 H), 1.32 (s, 6 H); MS LC-MS (MH+=193).

Workup

  1. filtrationThe catalyst was filtered of and EtOH
  2. customwas removed under reduced pressure
  3. washThe crude material was then washed with dichloromethane (2×50 mL)

Sources & evidence

ORD record
ord-dea1a53b4d0244009e64845c3433cf09
Source dataset
uspto-grants-2006_12
Patent number
US07144885B2

Reaction notes

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