Reaction Steps
A mixture of 3-acetoxy-6-chloro-3,7-dimethyl-1,7-octadiene (11.5 g, 0.05 mol), prepared according to Example 1, potassium acetate (14.7 g, 0.15 mol), and copper (II) acetate monohydrate (2 g, 0.01 mol) in N,N-dimethylacetamide (50 mL) was stirred for 9 h at 100° C. The reaction mixture was poured into water and extracted with diethyl ether. The extracts were washed with 5% sodium bicarbonate (50 mL) and brine (50 mL). Evaporation of the solvent and distillation afforded 9.5 g of distillate as a mixture (GLC) of (E)-3,8-diacetoxy-3,7-dimethyl-1,6-octadiene (55%), (Z)-3,8-diacetoxy-3,7-dimethyl-1,6-octadiene (5%) and 3,6-diacetoxy-3,7-dimethyl-1,7-octadiene (34%). These isomers can be separated by preparative GLC. The (Z)- and (E)-mixture can be separated from the internal diacetoxy derivative by careful distillation. (Z)-isomer: IR (film) 1740, 1370, 1240, 1020 cm-1. NMR (CDCl3) δ 1.53 (3H, s), 1.77 (3H, s), 1.97 (3H, s), 2.03 (3H, s), 1.8-2.4 (4H, complex), 4.57 (2H, s), 5.0-5.67 (3H, m), 6.0 (1H, dd). MS (m/e) 43, 119, 41, 45. (E)-isomer: IR (film) 1740, 1370, 1240, 1020 cm-1. NMR (CDCl3) δ 1.53 (3H, s), 1.64 (3H, s), 1.97 (3H, s), 2.03 (3H, s), 1.8-2.4 (4H, complex), 4.43 (2H, s), 5.0-5.6 (3H, m), 6.0 (1H, dd). MS (m/e) 43, 119, 41, 45. Internal isomer: IR (film) 1740, 1370, 1240, 1020 cm-1. NMR (CDCl3) δ 1.64 (3H, s), 2.00 (3H, s), 2.03 (3H, s), 2.07 (3H, s), 1.8-2.4 (4H, m), 4.33 (1H, m), 4.83-5.50 (4H, m), 6.00 (1H, dd). MS (m/e) 43, 41, 119, 67.
