Pyridine → HCID 86737370, compound

HRID 1732219Notes

Reaction equation

HRID 1732219 reaction equation
N1C=CC=CC=1.[CH2:7]([O:14][CH:15]1[CH2:20][CH2:19][CH2:18][C:17]2([O:24][CH2:23][CH2:22][O:21]2)[C:16]1([CH3:31])[CH2:25][CH2:26][CH2:27][CH:28]([OH:30])[CH3:29])[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1>C(Cl)Cl.CCOCC.[O-2].[O-2].[O-2].[Cr+6]>[CH2:7]([O:14][CH:15]1[CH2:20][CH2:19][CH2:18][C:17]2([O:21][CH2:22][CH2:23][O:24]2)[C:16]1([CH3:31])[CH2:25][CH2:26][CH2:27][C:28](=[O:30])[CH3:29])[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1

Participants

6

Reactant 2

HCID 1049PyridineHCID 86737369HCID 86737369, compound

Product 1

HCID 86737370HCID 86737370, compoundYield 61.2%

Reagents, catalysts & solvents 3

HCID 10219390chromium (VI) trioxideCatalystHCID 3283Diethyl EtherSolventHCID 6344DichloromethaneSolvent2×

Conditions

Temperature
23 °C

Procedure

A solution of pyridine (70.3 g, 0.89 mol) and chromium trioxide (44.5 g, 0.445 mol) in methylene chloride (1.8 l) in a nitrogen atmosphere is stirred for 45 minutes. Celite (180 g) is added followed by (2S*, 3R*)-3-benzyloxy-1,1-ethylenedioxy-2-methyl-2-(4'-hydroxypentyl)-cyclohexane (25.8 g, 0.074 mol) in methylene chloride (100 ml). The mixture is stirred for 90 minutes at 23° C. The mixture is then filtered and the celite cake is washed with methylene chloride (10×200 ml). The filtrate and washings are combined and the solvents are removed under reduced pressure to give a dark oil, which is diluted with ether (750 ml) and filtered. The ether phase is dried (MgSO4) and the solvents are removed at reduced pressure. The crude product (21 g) is chromatographed on SilicAR CC-7 (300 g, Mallinckrodt) in hexane. Elution with 6% ethyl acetate/hexane gives (2S*, 3R*)-3-benzyloxy-1,1-ethylenedioxy-2-methyl-2-(4'-oxopentyl)-cyclohexane as a clear colorless oil (15.7 g, 61%): ir (neat) 1712 cm-1 (CO); nmr (CDCl3)δ 1.06 (s, 3H, --CH3), 2.04 (s, 3H, ##STR50## 2.30 (m, 2H, --CH2 --CO), 3.50 (m, 1H, ##STR51## 3.98 (s, 4H, ketal), 4.55 (d of d, J=10 Hz, 2H, --O--CH2Ph), 7.20 (s, 5H, aromatic).

Workup

  1. additionCelite (180 g) is added
  2. filtrationThe mixture is then filtered
  3. washthe celite cake is washed with methylene chloride (10×200 ml)
  4. customthe solvents are removed under reduced pressure
  5. customto give a dark oil, which
  6. filtrationfiltered
  7. dry with materialThe ether phase is dried (MgSO4)
  8. customthe solvents are removed at reduced pressure
  9. customThe crude product (21 g) is chromatographed on SilicAR CC-7 (300 g, Mallinckrodt) in hexane
  10. washElution with 6% ethyl acetate/hexane

Sources & evidence

ORD record
ord-4a0bf762e045424c9f03af478b6f08f3
Source dataset
uspto-grants-1980_12
Patent number
US04237053

Reaction notes

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