Methyl Acetate → (3S,5S)-3,5-Dimethyl-3-((S)-2-methyl-propane-2-sulfinylamino)-heptanoic Acid Methyl Ester

Participants

Reaction Conditions

Reaction Steps

To a solution of diisopropylamine (3.1 mL, 22.2 mmol) in THF (40 mL) at −78° C. was slowly added butyllithium (14.4 mL, 1.6 M, 23 mmol). The mixture was stirred at 0° C. for 25 minutes and subsequently cooled down to −78° C. Methyl acetate (1.76 mL, 22.2 mmol) in THF (7 mL) was added. After Stirring for 20 minutes, chlorotitaniumtriisopropoxide (11 mL, 46.2 mmol) in THF (10 mL) was added and the resulting mixture was stirred at −78° C. for 20 minutes. (S)-2-Methyl-propane-2-sulfinic acid ((3S)-1,3-dimethyl-pentylidene)-amide (1.9 g, 8.9 mmol) in THF (10 mL) was added. The mixture was stirred at −78° C. overnight. The reaction was quenched by NH4Cl solution (50 mL). The mixture was filtered. The filtrate was extracted by EtOAc (3×70 mL). The EtOAc phase was reduced under reduce pressure and the residue was purified by a silica gel column (Hexane/EtOAc 1:1) to give the titled compound (1.61 g, 62% yield) as a colorless oil: 1H NMR (CDCl3) δ 3.64 (s, 3H), 2.60 (m, 2H), 1.47 (m, 2H), 1.44 (m, 1H), 1.36 (s, 3H), 1.27 (m, 2H), 1.19 (s, 9H), 0.90 (d, J=6.4 Hz, 3H), 0.81 (t, J=7.6 Hz, 3H); MS (APCI) (M+1)+ 292.2.

Provenance & Evidence