Chemo-enzymatic synthesis of key intermediates (S)-γ-hydroxymethyl-α,β-butenolide and (S)-γ-hydroxymethyl-γ-butyrolactone via lipase-mediated Baeyer-Villiger oxidation of levoglucosenoneElectronic supplementary information (ESI) available: 1H & 13C NMR spectra, and FT-IR spectra of LGO, HBO, 2-LGO and 2-HBO. See DOI: 10.1039/c4gc01231c

• Main Authors: Flourat, A. L, Peru, A. A. M, Teixeira, A. R. S, Brunissen, F, Allais, F
• Format: Journal Article
• Language: English
• Published: 22.12.2014
• ISSN: 1463-9262; 1463-9270
• DOI: 10.1039/c4gc01231c

Levoglucosenone ( LGO ), a valuable chiral platform chemical that can be efficiently produced from catalytic fast pyrolysis of cellulose, has been efficiently converted into optically pure ( S )-γ-hydroxymethyl-α,β-butenolide ( HBO ) using a two-step sequence involving a lipase-mediated Baeyer-Villiger oxidation and an acid hydrolysis. In the same fashion, ( S )-γ-hydroxymethyl-γ-butyrolactone ( 2H-HBO ) was successfully obtained through a three-step sequence (Baeyer-Villiger, palladium-catalysed hydrogenation and acid hydrolysis). The use of solid buffers in the lipase-mediated Baeyer-Villiger oxidation has proved beneficial in two ways: not only the reaction time and the enzymatic load were both reduced four-fold (from 8 to 2 hours and 464 to 113 U mmol −1 ) to reach conversions ≥83%, but solid buffers also prevented lipase from denaturation, thus preserving its enzymatic activity and allowing its use for further oxidation cycles. Baeyer-Villiger oxidation of levoglucosenone with CAL-B and solid buffers provided valuable lactones in high yields in only 2 hours while allowing enzyme recyclability.