Ammonium Chloride → HCID 69607407, compound

A solution of compound 2009 (0.374 g, 0.679 mmol) in anhydrous THF (10 ml) under argon was treated with isopropylmagnesium chloride (2 ml, 2M in THF, 5.43 mmol) at room temperature. The reaction was stirred until no starting material remained by TLC. Aqueous NH4Cl solution (10%, 15 ml) was added to quench the reaction and the THF was removed in vacuo. Distilled H2O (5 ml) was added and the solution extracted 3× with 15 ml CH2Cl2. The combined organic layers were washed with aqueous saturated NaCl solution (15 ml), dried over anhydrous MgSO4, filtered and the solvent removed in vacuo. Flash chromatography (SiO2, 12:1 hexanes:EtOAc) gave compound 2010 (0.3117 g, 77%) as a white foam. 1 H NMR (500 MHz, CDCl3) δ: 7.35-7.34 (m, 5H, benzyl Ar-H), 4.71-4.69 (m, 1H, THP ether methine H), 4.585 (d, J=11.9 Hz, 1H, benzyl-CH2), 4.31 (d, J=12.0 Hz, 1/2H, benzyl-CH2), 4.295 (d, J=12.0 Hz, 1/2H, benzyl-CH2), 3.94-3.91 (m, 1H, THP, OCH2), 3.62-3.58 (m, 1H, THP OCH2), 3.50-3.48 (m, 1H, C-3 H), 3.45 (s, 1H, C-7 H), 3.32-3.31 (m, 1H, C-24 H), 0.81 (s, 3H, C-19 H), 0.63 (d J=2.4 Hz, 3H, C-18 H) (Note: product is a mixture of diastereomers); IR (CHCl3) 3605, 2900 cm-1 ; MS (CI/isobutane) m/z 595 (M+1, 10%), 401 (M+1-THP-Bn-H2O, 25%), 385 (M+1-THP-HOBn, H2O, 100%); m.p. 55°-59° C.; Anal. calcd. for C39H62O4 : C=78.74, H=10.50; Found: C=78.65, H=10.54.