Methyl iodide → 3,3-Dimethyloxan-2-one

Temperature

-45 °C

The 3-methyltetrahydro-2H-pyran-2-one from Example 4(a) (5.6 g, 49.0 mmol) was slowly added to a cold (-78° C.) THF solution (50 ml) of LDA (54 mmol) so that the internal temperature did not exceed -65° C. After stirring for an additional 30 minutes, the acetone/CO2 bath was replaced with a CH3CN/CO2 bath and CH3I (10.4 g, 73.5 mmol) was added at a rate sufficient to maintain the internal temperature at -45° C. After stirring at -45° C. for an additional hour the reaction was allowed to warm to -30° C. and quenched by the dropwise addition of 10% HCl (21 ml). The resulting mixture was poured into ether (300 ml) and the ether layer was washed with saturated brine (50 ml), saturated NaHCO3 solution (20 ml), saturated brine (2×25 ml), dried (MgSO4) and evaporated to provide a pale yellow oil. This oil was distilled to give the title compound as a colorless liquid. b.p.0.2 54° C. NMR (CDCl3) δ 4.34 (2 H, m), 1.89 (2 H, m), 1.75 (2 H, m), 1.30 (6H, s).

1. customdid not exceed -65° C
2. stirringAfter stirring at -45° C. for an additional hour the reaction
3. temperatureto warm to -30° C.
4. customquenched by the dropwise addition of 10% HCl (21 ml)
5. additionThe resulting mixture was poured into ether (300 ml)
6. washthe ether layer was washed with saturated brine (50 ml), saturated NaHCO3 solution (20 ml), saturated brine (2×25 ml)
7. dry with materialdried (MgSO4)
8. customevaporated
9. customto provide a pale yellow oil
10. distillationThis oil was distilled

ORD record

ord-02b9fcd47cb048169e97309d0882ab42

Source dataset

uspto-grants-1989_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04851436