(Z)-oct-2-enal

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The above vinyl ether was dissolved in benzene (100 ml.) and the solution was refluxed for 120 hours under Argon. The solvent was removed at reduced pressure to give a yellow oil (~ 1.289 g.). This was chromatographed on 25 g. of silica gel and elution with 1:9 parts by volume of ether:petroleum ether (b.p. 30°-60°) gave 792 mg. of material. This was further purified by Kugelrohr distillation at 36°/0.5 mmHg to yield 3(S),7-dimethyl-4trans)octenal as a colorless oil, [α] D25 + 30.18° (c= 3.572, CHCl3). the solution was refluxed for 120 hours under Argon The solvent was removed at reduced pressure to give a yellow oil (~ 1.289 g.) This was chromatographed on 25 g of silica gel and elution with 1:9 parts by volume of ether petroleum ether (b.p. 30°-60°) gave 792 mg This was further purified by Kugelrohr distillation at 36°/0.5 mmHg

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 22.0 g (0.18 mol) of salicylaldehyde, 25.0 g (0.198 mol) of 2-octenal and 24.8 g (0.18 mol) of potassium carbonate in 200 ml of dioxane, maintained under an inert atmosphere, is heated at reflux for 2.5 h. The reaction mixture is subsequently brought to room temperature (20-25° C.) and then diluted by addition of 1.5 litres of water. The formation of an oil is observed, which oil is extracted with methylene chloride. The organic phase is dried over anhydrous sodium sulphate and then concentrated under reduced pressure. The title compound is thus obtained in a form of an orange oil, which oil is distilled under reduced pressure (B.p. (0.44 mm Hg): 132-140° C.). 20 g of the title product are obtained by distillation (48% yield). maintained under an inert atmosphere is heated at reflux for 2.5 h is subsequently brought to room temperature (20-25° C.) which oil is extracted with methylene chloride The organic phase is dried over anhydrous sodium sulphate concentrated under reduced pressure

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The above vinyl ether was dissolved in benzene (100 ml.) and the solution was refluxed for 120 hours under Argon. The solvent was removed at reduced pressure to give a yellow oil (~ 1.289 g.). This was chromatographed on 25 g. of silica gel and elution with 1:9 parts by volume of ether:petroleum ether (b.p. 30°-60°) gave 792 mg. of material. This was further purified by Kugelrohr distillation at 36°/0.5 mmHg to yield 3(S),7-dimethyl-4trans)octenal as a colorless oil, [α] D25 + 30.18° (c= 3.572, CHCl3). the solution was refluxed for 120 hours under Argon The solvent was removed at reduced pressure to give a yellow oil (~ 1.289 g.) This was chromatographed on 25 g of silica gel and elution with 1:9 parts by volume of ether petroleum ether (b.p. 30°-60°) gave 792 mg This was further purified by Kugelrohr distillation at 36°/0.5 mmHg