Methanol → 5-Methyl-3-phenyl-(S)-1H-inden-1-ol

Participants

Reaction Steps

(R)-MeCBS catalyst (0.22 ml, 1 M, 0.22 mmol) was mixed in 5 ml of dry THF, and stirred for 1 h at room temperature. After cooling to 0° C., 2.5 ml of 2 M BH3:Me2S (4.99 mmol) in THF were added. 5-Methyl-3-phenyl-inden-1-one (1.00 g, 4.54 mmol) was added as a solution in toulene (2 ml) over 2 h via a syringe pump. The reaction was followed by TLC. After completeness, methanol (0.6 ml, 17 mmol) was added at 0° C. and the mixture was evaporated to dryness. Flash chromatography eluting with ethyl acetate:pentane 10:90 gave 0.96 g (95%) of the title compound. Rf 0.35 (ethyl acetate:pentane 20:80) (ChiralCel OD-H) 0.5 ml/min of hexane/isopropanol: 95/5 (S)-isomer 24.53 min, (R)-isomer 27.22 min, 93% ee. IR (neat cm−1): 3300, 1605, 1446, 949, 813. 1H NMR δ: 1.40 (s, 1H), 2.40 (s, 3H), 5.27 (d, J=8 Hz, 1H), 6.43 (d J=2 Hz, 1H), 7.18 (d, J=8 Hz, 1H), 7.27 (s, 1H), 7.47 (m, 4H), 7.59 (m, 2H). 13C NMR δ: 21.6, 76.2, 121.6, 123.6, 126.9, 127.6, 128.2, 128.6, 134.1, 134.9, 138.2, 142.1, 143.7, 145.6. MS (EI 70 eV) m/z (rel. intensity): 220 (100) [M+], 207 (71), 178 (66), 144 (42), 116 (23).

Provenance & Evidence