(+)-Pantolactone → (S)-3,3-Dimethylbutane-1,2,4-triol

Temperatur

0 °C

To a 0° C. solution of 5.01 g (38.5 mmol) of (S)-(+)-pantolactone in 150 mL of methanol was carefully added 3.72 g (98.5 mmol) of sodium borohydride. After gas evolution had subsided, the ice-bath was removed and the reaction closely monitored, cooling to 0° C. with an ice-water bath as needed when gas evolution became vigorous. The ice-water bath was removed and the reaction mixture was stirred at room temperature for 4 h. Dowex 50W×4-400 (H+) resin was added to the solution until a pH of 7 was achieved, as indicated by wet pH paper. The resin was filtered off, and the filtrate was evaporated under reduced pressure. Portions of methanol and toluene were distilled from the resulting oil, which was further dried under high vacuum to afford 5.16 g (quantitative yield) of (2S)-3,3-dimethyl-1,2,4-butanetriol. 1H NMR (300 MHz, CDCl3) δ 3.49-3.82 (m, 5H), 3.11 (d, J=4 Hz, 1H), 2.62 (m, 1H), 2.42 (m, 1H), 0.98 (d, J=6 Hz, 6H).

1. customTo a 0° C.
2. customthe ice-bath was removed
3. customthe reaction
4. customThe ice-water bath was removed
5. additionDowex 50W×4-400 (H+) resin was added to the solution until a pH of 7
6. filtrationThe resin was filtered off
7. customthe filtrate was evaporated under reduced pressure
8. distillationPortions of methanol and toluene were distilled from the resulting oil, which
9. customwas further dried under high vacuum

ORD-Eintrag

ord-9228e78d6ac14ace91ffd30d402ce040

Quelldatensatz

uspto-grants-2008_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07402606B2