反应详情

To a 3 L, 3-necked round-bottomed flask equipped with a mechanical stirrer and two glass stoppers at room temperature were added E-1,2-diphenylethene (Trans-stilbene) (180.25 g, 1.0 mol, 1.0 eq), 4-methylmorpholine N-oxide (260 mL of a 60% by wt. aqueous solution (1.5 mol, 1.5 eq) dihydroquinidine 4-chlorobenzoate (23.25 g, 0.05 mol, 0.05 eq) 375 mL acetone and 7.5 mL H2O. The solution was 0.1M in alkaloid M in olefin, and the solvent was 25% water/75% acetone (v/v). The flask was immersed in a 0° C. cooling bath and stirred for 1 h. Osmium tetroxide (1.0 g, 4.0 mmol., 4.0×10-3 eq) was added in one portion producing a milky brown-yellow suspension. The reaction mixture was then stirred at 0° C. for 24 h and monitored by silica TLC (3:1 CH2Cl2 :Et2O v/v). At this point, sodium metabisulfite (285 g, 1.5 mol) was added, the mixture was diluted with 500 mL of CH2Cl2, warmed to room temperature, and stirred at room temperature for 1 h. Anhydrous sodium sulfate (50 g) was added and the mixture was stirred at room temperature overnight. The suspension was filtered through a 20 cm Buchner funnel, the filtrand was rinsed thoroughly with acetone (3×250 mL), and the filtrate was concentrated to a brown paste on a rotary evaporator with slight heating (bath temperature 30°-40° C). The paste was dissolved in 3.5 L of EtOAc, transferred to a 6 L separatory funnel and washed sequentially with H2O (2×500 mL), and brine (1×500 mL). The initial aqueous washes were kept separate from the subsequent acid washes which were retained for alkaloid recovery. The organic layer was dried (Na2SO4), and concentrated to give the crude diol in quantitative yield (222.7 g, 1.04 mol, 104%). The ee of the crude product was determined by 1H NMR analysis of the derived bis-Mosher ester to be 90%. One recrystallization from hot 95% acueous ethanol (3 mL/g) afforded 172-180 g (80-84%) of enantiomerically pure stilbene diol as a white solid, mp 145.5°-146.5° C., [α]D25 =91.1° (c=1.209, abs EtOH).

1. customTo a 3 L, 3-necked round-bottomed flask equipped with a mechanical stirrer
2. customwas immersed in a 0° C.
3. temperaturecooling bath
4. customproducing a milky brown-yellow suspension
5. stirringThe reaction mixture was then stirred at 0° C. for 24 h
6. stirringstirred at room temperature for 1 h
7. stirringthe mixture was stirred at room temperature overnight
8. filtrationThe suspension was filtered through a 20 cm Buchner funnel
9. washthe filtrand was rinsed thoroughly with acetone (3×250 mL)
10. concentrationthe filtrate was concentrated to a brown paste on a rotary evaporator
11. temperaturewith slight heating (bath temperature 30°-40° C)
12. dissolutionThe paste was dissolved in 3.5 L of EtOAc
13. customtransferred to a 6 L separatory funnel
14. washwashed sequentially with H2O (2×500 mL), and brine (1×500 mL)
15. customThe initial aqueous washes were kept separate from the subsequent acid washes which
16. dry with materialThe organic layer was dried (Na2SO4)
17. concentrationconcentrated
18. customto give the crude diol in quantitative yield (222.7 g, 1.04 mol, 104%)
19. customOne recrystallization from hot 95% acueous ethanol (3 mL/g)