2-Cyclopenten-1-one → Ethyl 2-oxobicyclo[3.1.0]hexane-6-carboxylate

Temperature

-78 °C

To a suspension of (ethoxycarbonylmethyl)dimethylsulfonium bromide (148.5 g, 0.648 mole) in acetonitrile (1170 ml) was added 1,8-diazabicyclo[5.4.0]undec-7-ene (97 ml, 0.648 mole) at 22° C. and stirring was continued for 45 min. The solution was treated with 2-cyclopenten-1-one (63 ml, 0.778 mole) and stirring was continued at 22° C. and light exclusion for 4 d. The mixture was evaporated to a volume of ca. 500 ml, partitioned between 1N aqueous HCl and diethylether, the organic layer was dried, evaporated and purified over silica (150 g) using cyclohexane/AcOEt (9:1). The material was dissolved in diethylether (50 ml) and n-pentane (50 ml), briefly cooled to −78° C. until the material precipitated, filtered and the residue was dried to give the title compound as white crystals.

1. stirringstirring
2. customwas continued at 22° C.
3. waitlight exclusion for 4 d
4. customThe mixture was evaporated to a volume of ca. 500 ml
5. custompartitioned between 1N aqueous HCl and diethylether
6. customthe organic layer was dried
7. customevaporated
8. custompurified over silica (150 g)
9. dissolutionThe material was dissolved in diethylether (50 ml)
10. customprecipitated
11. filtrationfiltered
12. customthe residue was dried

ORD record

ord-60d1d7e1b92248b9afc921d37a09a8e1

Source dataset

uspto-grants-2014_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08815881B2