1,4-Dioxaspiro[4.5]decan-8-one → 8-Methylidene-1,4-dioxaspiro[4.5]decane

HRID 520405Notes

Reaction equation

HRID 520405 reaction equation
O([C:3]([CH3:6])([CH3:5])[CH3:4])[K].BrP(C)(C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[O:28]1[C:32]2([CH2:37]CC(=O)C[CH2:33]2)[O:31][CH2:30][CH2:29]1>CCOCC>[CH2:4]=[C:3]1[CH2:6][CH2:37][C:32]2([O:31][CH2:30][CH2:29][O:28]2)[CH2:33][CH2:5]1

Participants

5

Reactant 3

HCID 5674151,4-Dioxaspiro[4.5]decan-8-oneHCID 621706HCID 621706, compoundHCID 178418922HCID 178418922, compound

Product 1

HCID 109537438-Methylidene-1,4-dioxaspiro[4.5]decaneYield 24.3%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

A mixture of KO-tBu (7.4 g, 65.9 mmol) and bromo(methyl)triphenylphosphorane (21.6 g, 60.5 mmol) in ether (100 mL) was refluxed for 0.5 h. Then a solution of 1,4-dioxaspiro[4.5]decan-8-one (6.24 g, 40.0 mmol) in ether (100 mL) was added dropwise during 1.5 h. The reaction mixture was stirred for 2 h, cooled to rt, filtered and the filtrate was concentrated. The residue was purified by silica gel chromatography (EtOAc/hexane) to afford 8-methylene-1,4-dioxaspiro[4.5]decane (1.5 g) as a clear oil. 1H NMR (400 MHz, CDCl3) δ ppm 4.62-4.74 (2H, m), 3.98 (4H, s), 2.30 (4H, dd, J=7.03, 6.02 Hz), 1.66-1.77 (4H, m).

Workup

  1. temperaturewas refluxed for 0.5 h
  2. filtrationfiltered
  3. concentrationthe filtrate was concentrated
  4. customThe residue was purified by silica gel chromatography (EtOAc/hexane)

Sources & evidence

ORD record
ord-2bc330d9035147f58c0133c5a44887da
Source dataset
uspto-grants-2016_05
Patent number
US09326973B2

Reaction notes

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