Water → HCID 10899000, compound

Participants

Reaction Steps

To a clear yellow solution of K2OsO2(OH)4 (246.1 mg, 0.67 mmol, 0.95 mol %), hydroquinine 1,4-phthalazinediyl diether (555.1 mg, 0.71 mmol, 1.01 mol %), N-methylmorpholine N-oxide (50 wt % in water, 25.0 mL, 0.106 mol, 1.51 equiv.), t-BuOH (84 mL), and [120 (58 mL) was added at 25° C. the neat olefin XV (R1=i-Pr; R3=Me) (9.0 g, 70.2 mmol) via a syringe pump over a period of 48 h (the syringe was connected to tubing, whose tip was immersed in the solution throughout the reaction time). The resulting clear orange solution was then stirred for another 60 min, after which time ethyl acetate (200 mL) and a solution of Na2SO3 (15.0 g) in H2O (150 mL) were added, and the resulting mixture was stirred for 4 h. The phases were separated, and the aqueous layer was extracted with more ethyl acetate (2×). The organic layers were then combined and the chiral ligand was extracted from the organic phase with a solution of 0.3M H2SO4 in saturated Na2SO4 (2×100 mL). The phases were once again separated and the aqueous layer was extracted with more ethyl acetate (1×). The organic layers were combined and dried over Na2SO4, filtered and concentrated in vacuo. This afforded 11.4 g (ca. 100%) of a white oily solid which was shown to be 70% e.e (determined by 1H NMR from a 1:1 molar solution of diol and Europium tris[3-(heptafluoropropylhydroxymethylene)-(−)-camphorate] in C6D6). Recrystallisation from 35-60° C. petroleum ether afforded 6.8 g (60%) of (2R,3S)-Methyl 2,3-dihydroxy-3-[isopropyl]propionate (XVIb; R1=i-Pr; R3=Me) that was ca. 100% e.e., obtained as white crystals, mp=32-34° C.;=−110.6° (c 1.04, CHCl3)]. 1H NMR (300 MHz, CDCl3) δ4.28 (dd, J=5.6, 1.8 Hz, 1H), 3.80 (s, 3H), 3.48 (m, 1H), 3.28 (m, 1H), 2.33 (d, J=9.3 Hz, 1H), 1.87 (m, 1H), 1.02 (d, J=6.7 Hz, 3H), 0.95 (d, J=6.7 Hz, 3H).

Provenance & Evidence