3.1.26. (3*S*,4*S*)-7-chloro-5,8-dihydroxy-4-methoxy-3-pentylisochroman-1-one (**18**)

To a solution of monoMOM chloro derivative **18a** (3.3 mg, 9.20 μmol) in MeOH (0.69 mL) was added 6 M aqueous HCl (0.23 mL) at 0 ◦C. After stirring for 2 h at 40 ◦C, the reaction was quenched by adding saturated NaHCO3 at 0 ◦C. The mixture was extracted with EtOAc (×3) and the combined organic layers were washed with brine, dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was purified with PTLC (EtOAc:*n*-hexane = 1:9) to give chloro derivative **18** (2.1 mg, 73%) as a brown solid. m.p. 119-120 ◦C; 1H-NMR (400 MHz, CDCl3) δ 11.17 (1H, br-s), 7.34 (1H, s), 6.34 (1H, br-s), 4.82 (1H, br-s), 4.59 (1H, ddd, *J* = 2.8, 5.6, 8.4 Hz), 3.48 (3H, s), 2.03 (1H, m), 1.93 (1H, m), 1.64 (1H, m), 1.53 (1H, m), 1.51–1.35 (4H, overlapped), 0.98 (3H, t, *J* = 7.2 Hz); 13C-NMR (100 MHz, CDCl3) δ 168.7, 152.1, 145.6, 124.9, 122.8, 121.1, 108.5, 81.8, 69.6, 57.0, 31.5, 29.8, 24.8, 22.5, 14.0.; IR (KBr) 3282, 2958, 2929, 2860, 1681, 1437, 1198 cm<sup>−</sup>1; HRMS (ESI) *m*/*z* (M + H)<sup>+</sup> calculated for (C15H20O5Cl)<sup>+</sup> 315.0999, found 315.0998.

## 3.1.27. (3*S*,4*S*)-7-bromo-5,8-dihydroxy-4-methoxy-3-pentylisochroman-1-one (**19**)

To a solution of bromo derivative **2** (11.0 mg, 24.6 μmol) in MeOH (1.8 mL) was added 6 M aqueous HCl (0.62 mL) at 0 ◦C. After stirring for 3.5 h at 40 ◦C, the reaction was quenched by adding saturated aqueous NaHCO3 at 0 ◦C. The mixture was extracted with EtOAc (×3) and the combined organic layers were washed with brine, dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue was purified with PTLC (EtOAc:*n*-hexane = 1:9) to give bromo derivative **19** (8.6 mg, 97%) as a white solid. m.p. 132 ◦C; 1H-NMR (400 MHz, CDCl3) δ 11.26 (1H, s), 7.36 (1H, s), 6.00 (1H, br-s), 4.76 (1H, d, *J* = 2.7 Hz), 4.52 (1H, ddd, *J* = 2.7, 5.1, 8.3 Hz), 3.41 (3H, s), 1.95 (1H, m), 1.86 (1H, m), 1.70-1.50 (2H, overlapped), 1.40–1.25 (4H, overlapped), 0.91 (3H, t, *J* = 7.0 Hz); 13C-NMR

(125 MHz, CDCl3) δ 168.4, 153.0, 145.8, 127.9, 121.5, 111.6, 108.2, 81.4, 70.0, 57.0, 31.5, 29.6, 24.8, 22.5, 14.0.; IR (KBr) 3296, 2955, 2930, 2859, 1679, 1432, 1197 cm<sup>−</sup>1; HRMS (ESI) *m*/*z* (M + Na)<sup>+</sup> calculated for (C15H19O5BrNa)<sup>+</sup> 381.0314, found 381.0322.
