PL177008B1 - Method for the production of new acetals (E) -3-methyl-6-trimethylsilicon-4-hexene-1-alu - Google Patents

Abstract

1. A method for preparing new (E)-3-methyl-6-trimethylsilico-4-hexene-1-al acetals of the general formula 1, where R is a methyl or ethyl group, characterized in that (E)-3-methyl-6-trimethylsilico-4-hexene-1-al is reacted with a trialkyl orthoester of the general formula 2, where R is a methyl or ethyl group and R1 is a methyl group or a hydrogen atom, in the presence of catalytic amounts of pyridinium p-toluenesulfonate. 2. A method according to claim 1, characterized in that the trialkyl orthoester is a trialkyl orthoacetate.

Description

The subject of the invention is a process for the preparation of new (E) -3-methyl-6-trimethylsilicon-4-hexen-1-alu acetals of the general formula I, where R is a methyl or ethyl group.

The essence of the invention lies in the fact that (E) -3-methyl-6-trimethylsilicon-4-hexen-1-al is reacted with a trialkyl orthoester of the general formula 2, where R is a methyl or ethyl group and R1 is a methyl group or hydrogen, in the presence of catalytic amounts of pyridine p-toluenesulfonate. Preferably, the orthoester is a trialkyl orthoacetate.

The chemical compounds produced by the method according to the invention are characterized by pleasant aromas (the fragrance characteristics are given in the table) and can be used as ingredients in perfumery compositions.

The subject of the invention is explained in more detail in the examples of embodiments.

Example 1. A mixture of 2.8 g (0.015 mol) of (E) -3-methyl-6-trimethylsilicon-4-hexen-1-a1 and 1.8 g (0.017 mol) of trimethyl orthoformate in 5 ml of anhydrous methyl alcohol with the addition of 0.1 g of pyridine p-toluenesulfonate is heated for 24 hours at a temperature of about 40 ° C. The mixture was diluted with 70 ml of diethyl ether, washed successively with: water, saturated sodium carbonate solution, 5% copper (II) sulfate solution and brine, and then dried with anhydrous magnesium sulfate. The product is distilled under reduced pressure. 2.7 g of pure (E) -1,1-dimethoxy-3-methyl-6-trimethylsilicon-4-hexene were obtained, representing 79% of theory.

Example 2 In the same manner as in Example 1, 2.4 g (0.013 mol) of (E) -3-methyl-6-trimethylsilicon-4-hexen-1-alu are reacted with 2.2 g (0.015 mol) of triethyl orthoformate in 4 ml of anhydrous ethyl alcohol with the addition of 0.1 g of pyridine p-toluenesulfonate. The procedure of Example 1 is now followed. 2.75 g of pure (E) -1,1-diethoxy-3-methyl-6-trimethylsilicon-4-hexene are obtained, which is 81% of theory.

Example 3. A mixture of 3.1 g (0.017 mol) of (E) -3-methyl-6-trimethylsilicon-4-hexen-1-alu and 2.4 g (0.02 mol) of trimethyl orthoacetate in 5 ml of anhydrous methyl alcohol with addition of 0.1 g of pyridine p-toluenesulfonate, it is heated for 2 hours at a temperature of about 40 ° C and then left at room temperature for 24 hours. The mixture was diluted with 80 ml of diethyl ether, washed successively with: water, saturated sodium carbonate solution, 5% copper (II) sulfate solution and brine, and then dried with anhydrous magnesium sulfate. The product is distilled under reduced pressure. 3.2 g of pure (E) -1,1-dimethoxy-3-methyl-6-trimethylsilicon-4-hexene are obtained, which is 82% of theory.

Example 4 In the same manner as in Example 3, 2.9 g (0.016 mol) of (E) -3-methyl-6-trimethylsilicon-4-hexene-1-alu are reacted with 2.9 g (0.018 mol) of orthoacetate. 008 triethyl in the presence of 0.1 g of pyridine p-toluenesulfonate in 5 ml of anhydrous ethyl alcohol. The procedure is then as in Example 3. There are obtained 3.5 g of pure (E) -1,1-diethoxy-3-methyl-6-trimethylsilicon-4-hexene, which is 85% of theory.

The physical and spectral properties as well as the odor characteristics of the compounds obtained are presented in the table.

Table

Basic- nik R Boiling point ° C kPa nD ° ’Hnmr (CDCI3) b (ppm) IR film (cm ' ¹ ) Characteristic fragrant -CH 3 65 / 0.5 1.4382 -0.003 (s, 9H, -Si (CH3) 3) 0.99 (d, J = 6.6Hz, 3H, -CH (CH3) -) 1.41 (d, J = 6.8Hz, 2H, Si-CH2-CH =) 3.30; 3.32 (2s, 6H, -CH (OCH3) 2 4.41 (t, J = 5.9Hz, 1H, -CH2-CH (OCH3) 2) 5.13-5.51 (m, 2H, -CE = CH-) 1248 (s) 1128 (s) 1056 (s) 968 (s) 848 (s) intense, pleasant, fruit- floral with a hint of apricot -CH2CH3 76 / 0.5 1.4381 0.003 (s, 9H, -Si (CH3) 3) 0.99 (d, J = 6.6Hz, 3H, -CH (CH3) -) 1.22 (t, J = 7.1Hz, 6H, -CH (OCH2CH3) 2) 1.41 (d, J = 6.8Hz, 2H, Si-CH2-CH =) 3.55; 3.59 (2k, J = 7.1Hz, 4H, -CH (OCH2CH3) 2 4.54 (t, J = 5.9Hz, 1H, -CH-CHCOC ^ C ^ h) 5.14-5.42 (m, 2H, -CH = CH-) 1248 (s) 1128 (s) 1064 (s) 968 (s) 848 (s) intense, floral with a hint of lily flower (lilium candidum)

rn 008

Formula 1

R ¹ C (OR) ₃ Formula 2

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Claims (2)

Patent claims 1. The method of producing new acetals (E) -3-me ^ ylo-6-tri ^^^^ / l <^ l ^ i ~ zz ^ im ^ - ^^ - ^ l ^^ l ^ i ^^^^ 1- alu, of the general formula I, where R is a methyl or ethyl group, characterized in that (E) -3-methyl-6-trimethylsilicon-4-hexene-1 -al is reacted with a trialkyl orthoester of general formula Formula 2, where R is a methyl or ethyl group and R 1 is a methyl group or a hydrogen atom in the presence of catalytic amounts of pyridine p-toluenesulfonate. 2. The method according to p. The process of claim 1, wherein the trialkyl orthoester is a trialkyl orthoacetate.