تفاعل #155568

معادلة التفاعل

(2R)-2-[(benzyloxy)methyl]oxirane

vinylmagnesium bromide

→

product

(2R)-1-(benzyloxy)pent-4-en-2-ol

المذيبات

tetrahydrofuran

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةwas maintained below −70° C
2. 2
   workup.ADDITIONUpon completion of the addition
3. 3
   أخرىthe cooling bath was removed
4. 4
   workup.WAITthe reaction mixture was left
5. 5
   workup.STIRRINGto stir at room temperature for 1 hour
6. 6
   أخرىquenched by slow addition of aqueous ammonium chloride solution (200 mL)
7. 7
   استخلاصAfter dilution with additional aqueous ammonium chloride solution (1.5 L) and ethyl acetate (1.5 L), the aqueous layer was extracted with ethyl acetate (1 L)
8. 8
   غسيلthe combined organic layers were washed with aqueous ammonium chloride solution (1.5 L)
9. 9
   تجفيفdried over magnesium sulfate
10. 10
    ترشيحfiltered
11. 11
    تركيزconcentrated in vacuo

الإجراء التجريبي

To a solution of (2R)-2-[(benzyloxy)methyl]oxirane (167 g, 1.02 mol) in tetrahydrofuran (2 L) was added copper(I) iodide (11.62 g, 61.02 mmol) at room temperature. The mixture was stirred for 5 minutes, then cooled to −78° C. A solution of vinylmagnesium bromide (1 M in tetrahydrofuran, 1.12 L, 1.12 mol) was added drop-wise over 1 hour while the reaction temperature was maintained below −70° C. Upon completion of the addition, the cooling bath was removed and the reaction mixture was left to stir at room temperature for 1 hour, then quenched by slow addition of aqueous ammonium chloride solution (200 mL). After dilution with additional aqueous ammonium chloride solution (1.5 L) and ethyl acetate (1.5 L), the aqueous layer was extracted with ethyl acetate (1 L) and the combined organic layers were washed with aqueous ammonium chloride solution (1.5 L), dried over magnesium sulfate, filtered, and concentrated in vacuo. Three batches of this reaction were carried out and combined to give the product as an orange oil. Yield: 600 g, 3.1 mmol, quantitative. 1H NMR (400 MHz, CDCl3) δ 7.28-7.40 (m, 5H), 5.78-5.90 (m, 1H), 5.08-5.17 (m, 2H), 4.57 (s, 2H), 3.86-3.94 (m, 1H), 3.53 (dd, J=9.6, 3.3 Hz, 1H), 3.39 (dd, J=9.6, 7.4 Hz, 1H), 2.26-2.34 (m, 3H).

المصدر