Propanal → HCID 57333635, compound

Temperature

23 °C

To ethyl glyoxylate polymer obtained by concentrating 47% toluene solution (108.6 mg, 0.5 mmol) were added (S)-2-[bis(3,5-bis(trifluoromethyl)phenyl)hydroxymethyl]pyrrolidine in an amount shown in Table 2 (the amount relative to ethyl glyoxylate (in monomer amount)), propanal (43.5 mg, 0.75 mmol), acetonitrile (0.5 ml, 1 M) and water (27.3 μL, 1.5 mmol). The reaction mixture was stirred at 23° C. for 24 hr, and Ph3P═CHCO2Et (348 mg, 1.0 mmol) was added thereto. The reaction mixture was stirred at 23° C. for 24 hr, and filtered through silica gel pad to quench the Wittig reaction, and the filtrate was concentrated under reduced pressure. The residue was purified by preparative thin layer chromatography (ethyl acetate:hexane=1:2) to give 1,6-diethyl (4R,5R,E)-5-hydroxy-4-methylhex-2-enedioate. The yield, syn/anti ratio and enantiomeric excess are shown in Table 2. The yield is calculated as a yield in 2 steps. The syn/anti ratio was measured by 1H-NMR spectrum. The enantiomeric excess was measured by HPLC using CHIRALCEL OB-H column (iPrOH:hexane=1:100, 1 mL/min).

1. stirringThe reaction mixture was stirred at 23° C. for 24 hr
2. filtrationfiltered through silica gel pad
3. customto quench
4. customthe Wittig reaction
5. concentrationthe filtrate was concentrated under reduced pressure
6. customThe residue was purified by preparative thin layer chromatography (ethyl acetate:hexane=1:2)

ORD record

ord-6aab17c22e724932a562649b1637e2e6

Source dataset

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08729294B2