... European Journal of Medicinal Chemistry. ... Department of Medicinal Chemistry and Department ... in a freezer for several months; R f 0.85 (petroleum ether–EtOAc 2:1). 1 H-NMR (300 MHz, CDCl 3 ): δ 0.98 (3H, t, J=7.3 Hz, H-4), 1.74 (2H, sextet, J=7.3 Hz, H-3), 2.57 (2H, t, J=7.3 Hz ...