(Dimethyl sulfide)trihydroboron → (3S,5R)-3-Hydroxymethyl-5-methyl-nonanoic Acid Tert-butyl Ester

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Reaction Steps

To a solution of the crude acid 139 (6.14 mmol) in 30 mL THF at 0° C. was added borane-dimethyl sulfide complex (2.0 M solution in THF, 4.6 mL, 9.2 mmol), and the mixture was allowed to warm slowly to ambient temperature overnight. Additional BH3-DMS was added until the acid was completely consumed (ca. 5 mL). The reaction was quenched by addition of MeOH, then partitioned between Et2O and sat. NaHCO3 (aq). The phases were separated, and the organic phase washed with brine, dried (MgSO4), and concentrated to provide alcohol 140. LRMS: m/z 226.1; 1H NMR (CDCl3): δ 3.63 (dd, J=11.0, 4.2 Hz, 1H), 3.42 (dd, J=11.0, 6.8 Hz, 1H), 2.30 (dd, J=14.9, 7.6 Hz, 1H), 2.20 (dd, J=14.9, 5.6 Hz, 1H), 2.03 (m, 2H), 1.42 (s, 9H), 1.24 (m, 6H), 1.02 (m, 2H), 0.85 (m, 6H). The crude product was used without purification.

Provenance & Evidence