Lithium tri-s-butylborohydride → HCID 66692593, compound

Participants

Reaction Steps

Preparation of (2,3-Cis)-5,7-dimethyl-2-(3,4,5-tribenzyloxyphenyl)chroman-3-ol (30): The cis 3-flavanol 30 was synthesized by the stereoselective L-selectride reduction of the 3-flavanone 29 in the same manner as given for 3-flavanol 23 (Scheme 3). The final product was obtained as a colorless oil (62% yield), after flash chromatography on silica gel using 20% of ethyl acetate in hexanes. 1H NMR (300 MHz, CDCl3): δ 1.73 (s, 1H, OH), 2.20 (s, 3H, CH3, 2.27 (s, 3H, CH3), 2.83 (d, J=17.1 Hz, 1H, 4-H), 2.95 (dd, J=4.2, 17.1 Hz, 1H, 4-H), 4.23–4.28 (m, 1H, 3-H), 4.87 (s, 1H, 2-H), 5.06 (s, 2H, OCH2Ph), 5.13 (s, 4H, OCH2Ph), 6.66 (s, 1H, 8-H), 6.68 (s, 1H, 6-H), 6.81 (s, 2H, 2′,6′-H), 7.25–7.43 (m, 15H, Ar—H). MS (ESI, positive ion) 595 (M+Na), 1167 (2M+Na).

Provenance & Evidence