3-Ethoxycyclohex-2-ene-1-one → Spiro[2.5]octan-5-one

3-Ethoxycyclohex-2-enone (25 g) was dissolved in diethyl ether (500 mL), and tetraisopropoxytitanium (55 mL) was added, followed by the addition of ethyl magnesium bromide (3.0M in diethyl ether, 180 mL) over 30 minutes. The reaction was stirred at room temperature for another two hours, and quenched by the careful addition of water (250 mL). The mixture was filtered through diatomaceous earth, and rinsed with diethyl ether. The filtrate was transferred to a separatory funnel, the aqueous layer was drawn off, and p-toluenesulfonic acid monohydrate (2 g) was added to the organic layer, which was stirred at room temperature for two days. The reaction mixture was washed with saturated aqueous NaHCO3 and brine, then dried over Na2SO4. The mixture was filtered, and concentrated and chromatography on silica gel using 93/7 hexanes/ethyl acetate provided the title compound.

1. customquenched by the careful addition of water (250 mL)
2. filtrationThe mixture was filtered through diatomaceous earth
3. washrinsed with diethyl ether
4. customThe filtrate was transferred to a separatory funnel
5. additionp-toluenesulfonic acid monohydrate (2 g) was added to the organic layer, which
6. stirringwas stirred at room temperature for two days
7. washThe reaction mixture was washed with saturated aqueous NaHCO3 and brine
8. dry with materialdried over Na2SO4
9. filtrationThe mixture was filtered
10. concentrationconcentrated

ORD record

ord-079cb49ef6104a1fb5c37f0ea4c986e5

Source dataset

uspto-grants-2014_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08889675B2