Methyl iodide → Ethyl 8-methyl-1,4-dioxaspiro[4.5]decane-8-carboxylate

Temperature

-78 °C

To a 100 mL round-bottom flask was charged THF (8 mL). The flask was flushed with argon, sealed, and fitted to balloon containing argon. The flask was cooled to −78° C. in dry ice/IPA bath. To this solution was added ethyl 1,4-dioxaspiro[4.5]decane-8-carboxylate (Int-5a, 2.28 g, 10.64 mmol) in 8 mL THF. The resulting solution was allowed to remain at −78° C. while LiHMDS (1.0 M in THF, 12.34 mmol, 12.34 mL) was added dropwise. Upon completion of addition, the solution was allowed to warm to 0° C. in ice bath. The reaction was stirred at 0° C. for one hour, at which point it was cooled back to −78° C. in dry ice/IPA bath. At this point, iodomethane (750 μL, 12.02 mmol) in THF (8 mL) was added dropwise. The reaction was allowed to gradually warm to room temperature as it was stirred overnight. After 18 hours, the reaction was quenched with sat NH4Cl(aq) and extracted with Et2O (x2). The combined organic extracts were washed with H2O (x1), saturated brine (x1), and dried over Na2SO4 and the residue were purified via silica gel chromatography to yield the title compound as a clear oil. Yield=1.44 g.

1. customThe flask was flushed with argon
2. customsealed
3. customfitted
4. additionto balloon containing argon
5. additionwas added dropwise
6. additionUpon completion of addition
7. temperatureto warm to 0° C. in ice bath
8. temperatureto gradually warm to room temperature as it
9. stirringwas stirred overnight
10. waitAfter 18 hours
11. customthe reaction was quenched with sat NH4Cl(aq)
12. extractionextracted with Et2O (x2)
13. washThe combined organic extracts were washed with H2O (x1), saturated brine (x1)
14. dry with materialdried over Na2SO4
15. customthe residue were purified via silica gel chromatography

ORD record

ord-0cc9d32be46b48e89d87a42cfcf0dd3c

Source dataset

uspto-grants-2013_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08609675B2