Hydrochloric Acid → HCID 10977875, compound

Participants

Reaction Steps

To an ether solution (15 ml) of 12b having an optical purity of 100% (M.P. 117°-120° C.; [α]D20 -37.9° (c=1.01, chloroform)) (670 mg, 2.66 mmole), an ether solution of methyl lithium (0.84 mmole/ml, 33 ml, 28.3 mmole) is gradually added in 1 hour and 20 minutes in an argon stream. The resultant mixture is stirred at room temperature for 30 minutes. After completion of the reaction, the reaction mixture is slowly poured into dilute hydrochloric acid (conc. hydrochloric acid: water=4:30) (270 ml) under stirring, and after saturation with sodium chloride, extracted with ether (150 ml×2). The ether extracts are combined, washed with a saturated aqueous solution of sodium hydrogen carbonate (20 ml), a 10% aqueous solution of sodium thiosulfate (10 ml) and a saturated aqueous solution of sodium chloride (20 ml) in order and dried over anhydrous magnesium sulfate. After filtration and evaporation, pale yellow needles (615 mg) are obtained. Purification by column chromatography (silica gel, 60 g; ether-hexane (4:1)) affords the objective 13b having an optical purity of 100% as pale yellow needles (420 mg, 63%). M.P. 119°-126° C. [α]D20 -47.4° (c=1.06, chloroform). The product is recrystallized from chloroform-ether to obtain an analytical sample as colorless needles. M.P. 128°-129° C. [α]D20 -48.2° (c=0.982, chloroform). IRνmaxNujol cm-1 : 3480 (OH), 1700 (COCH3). NMR (in CDCl3): 1.87 (2H, broad t, J=6.5 Hz, CH2CH2CCH2), 2.29 (3H, s, COCH3), 2.52-3.02 (4H, m, CH2CH2CCH2), 3.52 (1H, s, OH), 3.76 (3H, s, OCH3), 3.78 (3H, s, OCH3), 6.62 (2H, s, aromatic proton).

Provenance & Evidence