Acetic Acid → (6R,7R)-2,2-dimethyl-7-(1-hydroxy-1-methylethyl)-7-isocyano-1-aza-3-oxabicyclo[4.2.0]octan-8-one

Temperature

-70 °C

To a solution of (6R,7R)-2,2-dimethyl-7-isocyano-1-aza-3-oxabicyclo[4.2.0]octan-8-one (500 mg) in tetrahydrofuran (15 ml) was added a solution of n-butyllithium in hexane (2.33 ml of 1.55M solution) at -70° C. and the mixture was stirred at -70° C. for 15 minutes. A solution of acetone (0.265 ml) in tetrahydrofuran (2.4 ml) was added to the reaction mixture at -70° C. and the mixture was stirred at -70° C. for 25 minutes. Acetic acid (0.477 ml) was added to the mixture at -70° C. After stirring at -70° C. for 20 minutes, the mixture was evaporated in vacuo. The residue was dissolved in ethyl acetate (80 ml) and the solution was washed with aqueous sodium bicarbonate. The aqueous layer was separated and extracted with ethyl acetate (20 ml). The combined organic layers were washed with brine, dried over magnesium sulfate, and evaporated in vacuo. The crystalline residue was washed with isopropyl ether and filtered to give (6R,7R)-2,2-dimethyl-7-(1-hydroxy-1-methylethyl)-7-isocyano-1-aza-3-oxabicyclo[4.2.0]octan-8-one (460 mg).

1. stirringthe mixture was stirred at -70° C. for 25 minutes
2. stirringAfter stirring at -70° C. for 20 minutes
3. customthe mixture was evaporated in vacuo
4. dissolutionThe residue was dissolved in ethyl acetate (80 ml)
5. washthe solution was washed with aqueous sodium bicarbonate
6. customThe aqueous layer was separated
7. extractionextracted with ethyl acetate (20 ml)
8. washThe combined organic layers were washed with brine
9. dry with materialdried over magnesium sulfate
10. customevaporated in vacuo
11. washThe crystalline residue was washed with isopropyl ether
12. filtrationfiltered

ORD record

ord-e4b88d88ad0c4806a8f831ac99396877

Source dataset

uspto-grants-1985_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04539152