Trifluoroacetic acid → 5-ethyl-5-hydroxy-9-methoxy-4,5-dihydrooxepino[3,4-c]pyridin-3(1H)-one

Participants

Reaction Steps

tert-butyl 3-hydroxy-3-[3-(hydroxymethyl)-2-methoxy-4-pyridinyl]pentanoate (8.8 g, 28 mmol) is treated with trifluoroacetic acid (30 ml) for 3 hours at ambient temperature. The volatile components are evaporated off and the residue is purified by column chromatography (SiO2, CH2Cl2/MeOH: 100/0 to 98/2), which produces a limpid oil which, after treatment with toluene, produces 5.9 g of product (L) (89%) in the form of white crystals, m.p. 97-98° C.

Provenance & Evidence