2(3H)-Furanone, 4-(2-bromophenyl)dihydro- synthesis

Yield:80707-06-8 98%

Reaction Conditions:

with Candida antarctica Lipase type B;urea hydrogen peroxide adduct in ethyl acetate at 30; for 20 h;Enzymatic reaction;Baeyer-Villiger Ketone Oxidation;

Steps:

2.7 General procedure for the chemoenzymatic synthesis of lactones 2a-l using CAL-B, UHP and EtOAc

General procedure: Over a solution of the corresponding cyclobutanone 1a-l (0.25 mmol) in EtOAc (379 μL, 30.0 mmol), complex urea-hydrogen peroxide (UHP, 35 mg, 0.38 mmol) and CAL-B (12.5 mg) were added. The suspension was shaken for 20 h at 30 °C and 250 rpm, then an aliquot was analyzed by GC. The reaction was left shaken until complete conversion was reached, then water was added (2 mL) and the enzyme filtered off. The solution was extracted with EtOAc (3× 5 mL) and the organic phases combined and washed with water (2× 5 mL) and brine (5 mL). The resulting organic phase was dried over Na₂SO₄, filtered and the solvent was evaporated under reduced pressure to obtain the corresponding lactones 2a-l (51-99% isolated yield). For fluorinated lactone 2k a column chromatography on silica gel (30% EtOAc/hexane) was necessary, as the reaction did not lead to complete conversion.

References:

González-Martínez, Daniel;Rodríguez-Mata, María;Méndez-Sánchez, Daniel;Gotor, Vicente;Gotor-Fernández, Vicente [Journal of Molecular Catalysis B: Enzymatic,2015,vol. 114,p. 31 - 36]