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

To a solution of 3-ethoxycyclohex-2-enone (48.1 mL) in ether (1000 mL) was added titanium(IV) isopropoxide (110 mL) followed by addition of ethylmagnesium bromide (357 mL) at ambient temperature. The reaction mixture was stirred for 2 hours at ambient temperature and was then quenched with water (500 mL). The organic layer was separated (decanted) and the water layer was extracted with ether (3×300 mL). The combined extracts were partially concentrated to approximately 300 mL. p-Toluenesulfonic acid monohydrate (3.0 g) was added and the reaction mixture was stirred overnight at ambient temperature. The reaction mixture was then washed with saturated aqueous NaHCO3 solution, dried (MgSO4), filtered and concentrated. The concentrate was purified by fractional distillation (1st fraction b.p. 27° C. at 23 torr (not product), 2nd fraction (product) b.p. 75° C. at 8 torr).

1. customwas then quenched with water (500 mL)
2. customThe organic layer was separated
3. custom(decanted)
4. extractionthe water layer was extracted with ether (3×300 mL)
5. concentrationThe combined extracts were partially concentrated to approximately 300 mL
6. additionp-Toluenesulfonic acid monohydrate (3.0 g) was added
7. stirringthe reaction mixture was stirred overnight at ambient temperature
8. washThe reaction mixture was then washed with saturated aqueous NaHCO3 solution
9. dry with materialdried (MgSO4)
10. filtrationfiltered
11. concentrationconcentrated
12. distillationThe concentrate was purified by fractional distillation (1st fraction b.p. 27° C. at 23 torr (not product), 2nd fraction (product) b.p. 75° C. at 8 torr)

ORD record

ord-8367b248d11e4dc4b464d8925aa2e275

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09174982B2