7-hydroxy-3,7-dimethyloctanal

Conditions: temp:95.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 3 L four-necked flask equipped with a stirrer, a thermometer and a reflux condenser was charged with 1032 g (6.0 mol) of hydroxycitronellal, 520 g (6.4 mol) of a 37% by mass formaldehyde aqueous solution, 53 g (0.41 mol) of dibutyl amine and 10 g (0.09 mol) of hexanoic acid, and the contents in the flask were stirred while heating at 95° C. After the elapse of 40 min, it was confirmed that no hydroxycitronellal was present in the raw mixture, and then the mixture was cooled and separated into two layers. The thus separated organic layer was subjected to distillation treatment, thereby obtaining 1058 g (5.5 mol) of 3,7-dimethyl-2-methylene-7-hydroxyoctanal (purity as measured by gas chromatography: 95%) (yield based on theoretical amount: 92%). A 3 L four-necked flask equipped with a stirrer After the elapse of 40 min, it the mixture was cooled separated into two layers The thus separated organic layer was subjected to distillation treatment

Conditions: temp:95.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 3 L four-necked flask equipped with a stirrer, a thermometer and a reflux condenser was charged with 1032 g (6.0 mol) of hydroxycitronellal, 520 g (6.4 mol) of a 37% by mass formaldehyde aqueous solution, 53 g (0.41 mol) of dibutyl amine and 10 g (0.09 mol) of hexanoic acid, and the contents in the flask were stirred while heating at 95° C. After the elapse of 40 min, it was confirmed that no hydroxycitronellal was present in the raw mixture, and then the mixture was cooled and separated into two layers. The thus separated organic layer was subjected to distillation treatment, thereby obtaining 1058 g (5.5 mol) of 3,7-dimethyl-2-methylene-7-hydroxyoctanal (purity as measured by gas chromatography: 95%) (yield based on theoretical amount: 92%). A 3 L four-necked flask equipped with a stirrer After the elapse of 40 min, it the mixture was cooled separated into two layers The thus separated organic layer was subjected to distillation treatment

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

Procedure: A primary use for hydroxycitronellol is as an intermediate in the synthesis of hydroxycitronellal, (7-hydroxy-3,7-dimethyloctan-1-al), a widely used perfumery material. Conventionally, in this synthesis, a mixture of geraniol and nerol is prepared from beta-pinene via myrcene hydrochloride and is partially hydrogenated to produce citronellol. Citronellol is then hydrated under acid conditions to produce hydroxycitronellol. It has also been made from myrcene by preparing the dihydrochloride and then chlorodihydrogeranyl acetate, followed by saponification and hydrogenation.1 Conventionally, in this synthesis

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

Procedure: The starting material of Example 1 can be prepared as follows: 172.2 g. of hydroxycitronellal and 106.1 g. of orthoformic acid methyl ester are treated dropwise, while cooling with ice, with a solution of 0.5 g. of p-toluenesulphonic acid in 800 ml. of absolute methanol. After 2 hours, 5 g. of sodium acetate are added and the mixture is concentrated on a rotary evaporator at 50°C. Upon distillation, the residue yields pure 1,1-dimethoxy-3,7-dimethyl-7-octanol; boiling point = 102°C/0.4 mmHg; nD22 = 1.4400. while cooling with ice, with a solution of 0.5 g the mixture is concentrated on a rotary evaporator at 50°C Upon distillation

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

Procedure: Ethynylation of 212 g of 6,10-dimethylundeca-3-en-2-on-10-ol obtained by aldol condensation of hydroxycitronellal and acetone was carried out in the same manner as in example 20 except that hydroxycitronellal was used in place of pseudoionone and 269 g of a crude product was thus obtained.

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

Procedure: The ethynylation of 212 g of 6,10-dimethylundeca-3-en-2-on-10-ol obtained by aldol condensation of hydroxycitronellal and acetone with acetylene was worked out in the same manner as in example 9 except that hydroxycitronellal was used in place of pseudoionone and 269 g of a crude product was thus obtained.

Conditions: temp:95.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A 3 L four-necked flask equipped with a stirrer, a thermometer and a reflux condenser was charged with 1032 g (6.0 mol) of hydroxycitronellal, 520 g (6.4 mol) of a 37% by mass formaldehyde aqueous solution, 53 g (0.41 mol) of dibutyl amine and 10 g (0.09 mol) of hexanoic acid, and the contents in the flask were stirred while heating at 95° C. After the elapse of 40 min, it was confirmed that no hydroxycitronellal was present in the raw mixture, and then the mixture was cooled and separated into two layers. The thus separated organic layer was subjected to distillation treatment, thereby obtaining 1058 g (5.5 mol) of 3,7-dimethyl-2-methylene-7-hydroxyoctanal (purity as measured by gas chromatography: 95%) (yield based on theoretical amount: 92%). A 3 L four-necked flask equipped with a stirrer After the elapse of 40 min, it the mixture was cooled separated into two layers The thus separated organic layer was subjected to distillation treatment