Methoxymethyl-triphenylphosphonium chloride → (R)-5-(3-methoxyallyl)-2,2-dimethyl-1,3-dioxolan-4-one

Temperatur

0 °C

(Conditions modified from Duttone, F. E., et. al., J. Med. Chem. 2003, 46, 2057) To a stirred solution of (methoxymethyl)triphenylphosphonium chloride (1.19 g, 3.48 mmol) in anhydrous ether (50 mL) at −10° C. under nitrogen was added phenyllithium (1.93 mL, 3.48 mmol) 1.8 M solution in diethyl ether, over 1 minute using a syringe. The mixture was stirred at 0° C. for 30 minutes and then cooled to −78° C. A solution of (R)-2-(2,2-dimethyl-5-oxo-1,3-dioxolan-4-yl)acetaldehyde (Preparation D, Step B; 0.500 g, 3.16 mmol) in ether/THF 1:1 (50 mL) was introduced via addition funnel, and the reaction mixture was stirred at −78° C. for 1 hour and then warmed to ambient temperature and stirred for 4 hours. The crude was filtered and the residue was purified over silica gel (5-50% EtOAc in hexanes) to afford (R)-5-(3-methoxyallyl)-2,2-dimethyl-1,3-dioxolan-4-one (0.355 g, 1.90 mmol, 60% yield) as a clear, colorless oil (mixture of (E)- and (Z)-isomers).

1. temperaturecooled to −78° C
2. stirringthe reaction mixture was stirred at −78° C. for 1 hour
3. temperaturewarmed to ambient temperature
4. stirringstirred for 4 hours
5. filtrationThe crude was filtered
6. customthe residue was purified over silica gel (5-50% EtOAc in hexanes)

ORD-Eintrag

ord-9b5ff0320a184f0f99fb76ee06f2332a

Quelldatensatz

uspto-grants-2014_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08754226B2