Efficient high-stereoselectivity synthesis process of polysubstituted 3-cyclopenten-1-one

Abstract

This invention is a high-effective high-steroselectivity synthetic method for multi-substituted 3-cyclopentene-1-ketone. It is incldues the following steps: firstly, the derivative of 1,4-diiodo-1,3-butadiene dissolved in the solvent of ethyl ether or tetrachlorofuran reacts with n-butyl lithium or tert-butyl lithium under low temp., CO is further introduced,l quenching reaction is conducted, andthe pure product is obtained further through extracting, stripping, drying, concentrating and decontaminating. The said invented method is scientific and rational, is a most direct and most simple method, and the yield is high, and the product is easily decontaminated.

Description

field of invention

[0001] The field of the invention belongs to the synthesis of organic synthesis intermediates, in particular to a highly efficient and highly stereoselective synthesis method of multi-substituted 3-cyclopenten-1-ones. Background of the invention

[0002] Multi-substituted 3-cyclopenten-1-ones are important intermediates in organic synthesis. Due to the existence of carbonyl functional group, ring structure and 3-position double bond, a variety of useful cyclic compounds can be synthesized using 3-cyclopenten-1-one derivatives as raw materials. Although there are many reports on the synthesis method of 2-cyclopenten-1-one, there are deficiencies such as complex reaction process and low yield. Contents of the invention

[0003] The purpose of the present invention is to use carbon monoxide as a raw material to directly and simply cyclize 1,4-diiodo-1,3-butadiene derivatives that are readily available in synthesis, and to synthesize multi-substituted 3 wit...

Examples

example 1

[0025] One of the I class compounds in the structural formula (R 1 =R 2 =nPr): Synthesis of trans-2,3,4,5-tetra(n-propyl)-3-cyclopenten-1-one.

[0026] Under the protection of an inert gas (such as high-purity nitrogen), add 1 mmol of 4,7-diiodo-5,6-di(n-propyl )-4,6-quinadiene and 5 mL of anhydrous and oxygen-free treated ether solvent. First, the above ether solution was lowered to a lower temperature (-78°C to -55°C) with a cold bath (such as a dry ice-acetone bath), and then 4 mmol tert-butyllithium (1.6M, n-pentane solution) was added dropwise under magnetic stirring. ). After stirring the reaction at -78°C to -55°C for 1 hour, carbon monoxide was introduced for 30 minutes. After continuing to stir the reaction at a temperature of -78°C to -30°C for 30 minutes, about 1 mL of saturated aqueous ammonium chloride solution was added to quench the reaction. Extracted three times with petroleum ether (each 10mL). The extract was washed twice with water (10 mL each time) a...

example 2

[0028] The second of class I compound in the structural formula (R 1 =SiMe 3 , R 2 =n-Hex): Synthesis of trans-2,5-bis(trimethylsilyl)-3,4-bis(n-hexyl)-3-cyclopenten-1-one.

[0029] The synthetic route is basically the same as above. The starting material diiodide compound for this synthesis is 1,4-diiodo-1,4-bis(trimethylsilyl)-2,3-bis(n-hexyl)-1,3-butadiene. 0.319 g of pure product was obtained (purity>98%, colorless liquid). Isolated yield 81%. Partial characterization data of this compound are as follows. 13 C NMR (CDCl 3 , SiMe 4 ) δ1.03, 15.65, 24.24, 29.59, 29.93, 30.93, 33.33, 54.75, 134.94, 220.79.

example 3

[0031] One of the II class compounds in the structural formula (R 1 =R 2 =nPr): Synthesis of derivative y.

[0032] The synthetic route is basically the same as above. The starting material diiodide compound of this synthesis is x. 0.154 g of pure product was obtained (purity>98%, colorless liquid). Isolated yield 70%. The NMR and high-resolution mass spectrometry data of the compound are as follows. 1 H NMR (CDCl 3 , SiMe 4 )δ0.81(t, J=7.8Hz, 6H), 1.00-1.63(m, 12H), 1.75-2.00(m, 4H), 2.63(t, J=7.0Hz, 2H). 13 C NMR (CDCl 3 , SiMe 4 )δ13.43, 18.90, 21.81, 23.15, 30.18, 53.34, 134.26, 221.10. HRMS calcd for C 15 h 24 O 220.1827, found 220.1818.

field of invention

[0001] The field of the invention belongs to the synthesis of organic synthesis intermediates, in particular to a highly efficient and highly stereoselective synthesis method of multi-substituted 3-cyclopenten-1-ones. Background of the invention

[0002] Multi-substituted 3-cyclopenten-1-ones are important intermediates in organic synthesis. Due to the existence of carbonyl functional group, ring structure and 3-position double bond, a variety of useful cyclic compounds can be synthesized using 3-cyclopenten-1-one derivatives as raw materials. Although there are many reports on the synthesis method of 2-cyclopenten-1-one, there are deficiencies such as complex reaction process and low yield. Contents of the invention

[0003] The purpose of the present invention is to use carbon monoxide as a raw material to directly and simply cyclize 1,4-diiodo-1,3-butadiene derivatives that are readily available in synthesis, and to synthesize multi-substituted 3 wit...

Examples

example 1

[0025] One of the I class compounds in the structural formula (R 1 =R 2 =nPr): Synthesis of trans-2,3,4,5-tetra(n-propyl)-3-cyclopenten-1-one.

[0026] Under the protection of an inert gas (such as high-purity nitrogen), add 1 mmol of 4,7-diiodo-5,6-di(n-propyl )-4,6-quinadiene and 5 mL of anhydrous and oxygen-free treated ether solvent. First, the above ether solution was lowered to a lower temperature (-78°C to -55°C) with a cold bath (such as a dry ice-acetone bath), and then 4 mmol tert-butyllithium (1.6M, n-pentane solution) was added dropwise under magnetic stirring. ). After stirring the reaction at -78°C to -55°C for 1 hour, carbon monoxide was introduced for 30 minutes. After continuing to stir the reaction at a temperature of -78°C to -30°C for 30 minutes, about 1 mL of saturated aqueous ammonium chloride solution was added to quench the reaction. Extracted three times with petroleum ether (each 10mL). The extract was washed twice with water (10 mL each time) a...

example 2

[0028] The second of class I compound in the structural formula (R 1 =SiMe 3 , R 2 =n-Hex): Synthesis of trans-2,5-bis(trimethylsilyl)-3,4-bis(n-hexyl)-3-cyclopenten-1-one.

[0029] The synthetic route is basically the same as above. The starting material diiodide compound for this synthesis is 1,4-diiodo-1,4-bis(trimethylsilyl)-2,3-bis(n-hexyl)-1,3-butadiene. 0.319 g of pure product was obtained (purity>98%, colorless liquid). Isolated yield 81%. Partial characterization data of this compound are as follows. 13 C NMR (CDCl 3 , SiMe 4 ) δ1.03, 15.65, 24.24, 29.59, 29.93, 30.93, 33.33, 54.75, 134.94, 220.79.

example 3

[0031] One of the II class compounds in the structural formula (R 1 =R 2 =nPr): Synthesis of derivative y.

[0032] The synthetic route is basically the same as above. The starting material diiodide compound of this synthesis is x. 0.154 g of pure product was obtained (purity>98%, colorless liquid). Isolated yield 70%. The NMR and high-resolution mass spectrometry data of the compound are as follows. 1 H NMR (CDCl 3 , SiMe 4 )δ0.81(t, J=7.8Hz, 6H), 1.00-1.63(m, 12H), 1.75-2.00(m, 4H), 2.63(t, J=7.0Hz, 2H). 13 C NMR (CDCl 3 , SiMe 4 )δ13.43, 18.90, 21.81, 23.15, 30.18, 53.34, 134.26, 221.10. HRMS calcd for C 15 h 24 O 220.1827, found 220.1818.