Fig. 4. Synthesis of furan-embedded amide and ester derivatives.

Reaction conditions: 2 (0.1 mmol), amines or hydrochloride of amino acid esters (0.15 mmol, 1.5 equiv.), and Et₃N (0.2 mmol, 2.0 equiv.) in DCM (2.0 mL), and stirring for 48 h in an oil bath at 60 °C, unless otherwise noted. ^a2 (0.1 mmol), alcohols (0.15 mmol, 1.5 equiv.), and NaH (0.15 mmol, 1.5 equiv.) in dry THF (2.0 mL) at 0 °C, then warmed to 60 °C slowly and stirred for 1.0 h. All yields are isolated yields.