Lithium Hydroxide → HCID 57609740, compound

Participants

Reaction Steps

To a solution of methyl esters 59 (200 mg, 4.00 mmol) in THF/H2O (25 mL/4.5 mL) was added LiOH (1 M in H2O, 0.50 mL, 4.4 mmol) at 10° C. dropwise. The reaction mixture was stirred at ambient temperature for 12 h and THF was removed under reduced pressure. The aqueous layer was acidified to pH2 with 1 M HCl and extracted with CH2Cl2 (25 mL×3). The combined organic layer was washed with brine, dried over MgSO4, filtered and concentrated. The residue was purified by flash chromatography (1:3 EtOAc/hexanes) to give the desired acids 60 (155 mg, 80%) as a white solid. IR (neat) 3199, 1719, 1648, 1612 cm−1; 1H NMR (500 MHz, CDCl3) δ 7.18 (d, J=8.5 Hz, 2H), 6.89 (d, J=9.0 Hz, 2H), 4.69 (d, J=17.5 Hz, 1H), 4.54 (q, J=7.0 Hz, 1H), 4.34 (d, J=17.0 Hz, 1H), 3.80 (s, 3H), 3.64 (dd, J=5.5, 8.5 Hz, 2H), 2.49 (dd, J=7.0, 8.5 Hz, 2H), 1.91 (ddd, J=6.0, 8.5, 14.0 Hz, 1H), 0.69-1.70 (m, 28H); LRMS (ESI) Calcd. for C29H43NO5 [M+H] 486, found 486.

Provenance & Evidence