tert-Butyl 2-(3-(3-(3,4-dimethoxyphenyl)propanoyl)phenoxy)acetate → tert-Butyl {3-[3-(3,4-dimethoxyphenyl)-1-hydroxypropyl]phenoxy}acetate

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Reaction Steps

A solution of 1-(3-(tert-Butoxycarbonylmethoxy)phenyl)-3-(3,4-dimethoxyphenyl)propan-1-one (10) (3.0 g, 7.49 mmol) in THF (5 mL) at −20° C. was treated with a solution of (+)-B-chlorodiisopinocamphenylborane (2.9 g, 8.99 mmol) in THF (10 mL) at −20° C. The resulting mixture was allowed to stand in a −20° C. freezer for 48 h after which time the mixture was evaporated and treated with diethyl ether (25 mL) followed by diethanolamine (8 mL). The viscous mixture was allowed to stir at room temperature for 3 h, after which time, was filtered through a pad of Celite with the aid of diethyl ether. The cloudy filtrate was evaporated and flash chromatographed (silica gel, 30% 40% EtOAc/hexanes) to afford 2.72 g (90%) of a clear colorless oil. (95% ee by Chiracel HPLC, 25% i-PrOH/hexanes, retention time 44.4 min for the R-enantiomer and 35.7 mm for the S-enantiomer): IR (neat) 3525, 2935, 1750, 1515, 1150 cm−1; 1H NMR (CDCl3, 300 MHz) 7.30-7.25 (m, 2H), 6.99-6.73 (m, 5H), 4.68 (m, 1H), 453 (s, 2H), 3.88 (s, 3H), 3.87 (s, 3H), 2.72-2.63 (m, 2H), 2.12-1.97 (m, 2H), 1.50 (s, 9H); 13C NMR (CDCl3, 75 MHz) 168.4, 158.5, 149.3, 147.6, 146.9, 134.8, 130.0, 120.6, 119.5, 114.0, 112.6, 112.2, 111.7, 82.7, 74.1, 66.1, 56.3, 56.2, 41.0, 32.0, 28.4.

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