Propanal → HCID 57333635, compound

Participants

Reaction Conditions

Reaction Steps

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).

Provenance & Evidence