Formate → HCID 54155766, compound

Participants

Reaction Steps

A solution of the disodium salt of 2,4-dioxopentanoic acid (0.52 g, 3 mmol) and sodium formate (0.24 g, 3.5 mmol) in Tris buffer (5 mM; pH corrected to 7.5 with 2M HCl; 20 ml) was de-oxygenated by bubbling through nitrogen for 30 minutes. NADH (28 mg, 0.04 mmol), dithiothreitol (2 ml of a 1M aqueous solution), formate dehydrogenase (20 U) and R-lactate dehydrogenase (Staphylococcus epidermidis, Sigma, 500 U) were added successively at room temperature under nitrogen. The mixture was stirred under nitrogen for 69 hours, with periodic addition of dilute HCl (0.5M; 2.6 ml) from a burette to maintain the pH in the range 6.0-6.2. After acidification to pH2, water was removed by rotary evaporation at 40° C., followed by evacuation to 0.5 mm Hg (~0.65 mbar). The residue was subject to methanolysis using methanol (15 ml), trimethylorthoformate (15 ml) and TsOH (100 mg, 0.53 mmol) over 5.5 hours. The mixture was concentrated under a stream of nitrogen and transacetylated with PPTS (10 mg) and acetone (20 ml) over 1.5 hours. The title compound was obtained as pale yellow oil (0.23 g, 53%), having identical spectroscopic properties to the (S)-enantiomer (compound 6). 1H-NMR analysis of the corresponding Mosher derivative indicated that homochiral (>0.99% ee) product had been obtained with an [α]D24 of +11.3° (c=2.2, Me2CO).

Provenance & Evidence