Reacción #2033

Ecuación de reacción

triphenylphosphine

Br2

4,7-decadien-1-ol

NaHCO3

→

(4Z,7Z)-1-bromo-4,7-decadiene

Rendimiento 32.0%

Disolventes

CH2Cl2

CH2Cl2

CH2Cl2

water

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroInto the slightly yellow suspension that formed
2. 2
   workup.ADDITIONthe crude mixture of 4
3. 3
   workup.STIRRINGAfter stirring for 1 hour
4. 4
   ExtracciónThe mixture was extracted with pentane
5. 5
   workup.WAITwere stored overnight in a freezer
6. 6
   OtroIn this way, triphenylphosphine oxide could be crystallized
7. 7
   Otroremoved by filtration
8. 8
   workup.DISTILLATIONColumn chromatography followed by distillation at reduced pressure
9. 9
   Otroafforded 5 (3.48 g, 32% yield
10. 10
    Otro=80°-85° C./2.5 torr

Procedimiento

A solution of triphenylphosphine (20.9 g, 80 mmol) in CH2Cl2 (100 ml) was treated with Br2 (7.8 g, 49 mmol) in CH2Cl2 (15 mL, 0° C.) and the mixture was stirred at room temperature for 20 min. Into the slightly yellow suspension that formed, the crude mixture of 4 and 4Z,7Z)-4,7-decadien-1-ol (12.4 g) in CH2Cl2 (15 ml) was added dropwise. After stirring for 1 hour, a solution of saturated NaHCO3 (50 mL) and water (50 ml) were added. The mixture was extracted with pentane and combined extracts were stored overnight in a freezer. In this way, triphenylphosphine oxide could be crystallized and removed by filtration. Column chromatography followed by distillation at reduced pressure afforded 5 (3.48 g, 32% yield based on 1 of b.p. =80°-85° C./2.5 torr. 1H NMR (200 MHz) δ: 5.37 (m, 4H, CH=CH), 3.41 (t, J=6.6, 6.6 Hz, 2H, CH2 --Br), 2.80 (dd, J=6.4, 6.5 Hz, 2H, =CH--CH2 --CH=), 2.21 (dt, J=7.0, 6.9, 6.8, 6.9 Hz, 2H, CH2 -3), 2.07 (dq, J=7.4 Hz, CH2 -9), 1.91 (tt, J=6.7, 6.6, 7.0, 7.0, 2H, CH2 -2), 0.97 (t, J=7.5, 7.5 Hz, 3H, CH3). 13C NMR (100.6 MHz) δ: 132.1 (8), 129.8 (5), 127.6 (7), 127.0 (4), 33.4 (1), 32.5 (2), 25.6 (3), 25.5 (6), 20.6 (9), 14.3 (10). MS [EI, m/z (%)] 218 (M+, 15), 216 (17), 137 (6), 109 (13), 107 (18), 96 (14), 95 (78), 82 (18), 81 (74), 79 (22), 68 (27), 67 (100), 55 (17), 53 (15), 42 (11), 41 (38), 40 (40).

Fuente