Asymmetric synthesis of alkyl chrysanthemates

Claim 2

A process for the production of an optically active alkyl chrysanthemate which comprises reacting 2,5-dimethyl-2,4-hexadiene with an alkyl diazoacetate in the presence of a copper complex coordinated with a chiral Schiff base at a temperature in the range of -50° C to 150° C, said Schiff base having the formula: ##STR7## wherein C* is an asymmetric carbon atom, R 1 is selected from the group consisting of (a) alkyl groups whose carbon atom number is 1 - 10, and (b) aralkyl groups with or without alkoxy substituent(s), whose total carbon atom number is 7 - 20, R 2 is selected from aryl groups with alkoxy substituent(s), whose total carbon atom number is 7 -30, X may be substituted at 1 or 2 positions on the ring and is selected from the group consisting of (a) alkyl having 1 - 10 carbon atoms, (b) phenyl, (c) benzo, (d) alkoxy having 1 - 10 carbon atoms, (e) halogen and (f) nitro, and Y is a hydrogen atom and wherein the molar ratio of the said copper complex to alkyl diazoacetate is in the range of 0.001 -0.1.

Claim 3

The process of claim 1 in which said copper complex has the following structure: ##STR8## wherein R 1 , R 2 , X and Y are defined as in claim 1.

Claim 4

The process of claim 1 in which said copper complex has the following structure: ##STR9## wherein C*, R 1 , R 2 , X and Y are defined as in claim 1.

Claim 5

The process of claim 1 in which said chiral Schiff base is prepared by the reaction of a chiral amino alcohol of the formula: ##STR10## wherein C*, R 1 and R 2 are defined as in claim 1, and a salicylaldehyde derivative of the formula: ##STR11## wherein X and Y are defined as in claim 1.

Claim 6

The process of claim 2 in which said copper complex is prepared by the reaction of a chiral Schiff base of Claim 4 with a cupric salt.

Claim 7

The process of claim 3 in which said copper complex is prepared by the reaction of a chiral amino alcohol of Claim 4 with a copper complex of salicylaldehyde derivative of Claim 4.

Claim 8

The process of claim 1 in which R 1 is a. benzyl, b. 4-methoxyphenylmethyl, c. 4-isopropoxyphenylmethyl, d. 4-butoxyphenylmethyl, e. 4-benzyloxyphenylmethyl, f. methyl, g. isopropyl, h. isobutyl, or i. cyclohexylmethyl.

Claim 9

The process of claim 4 in which said salicylaldehyde derivative is a. salicylaldehyde, b. 3,5-dibromosalicylaldehyde, c. 3-ethoxysalicylaldehyde, or d. 2-hydroxy-1-naphthaldehyde.

Claim 10

The process of claim 3 in which said chiral Schiff base is either a (R)- or (S)-enantiomer of the following: a. N-salicylidene-2-amino-1,1-di(2-methoxyphenyl)-3-phenyl-1-propanol, b. N-salicylidene-2-amino-1,1-di(3-methoxyphenyl)-3-phenyl-1-propanol, or c. N-salicylidene-2-amino-1,1-di(2-methoxyphenyl)-4-methyl-1-pentanol.

Claim 11

The process according to claim 1, wherein the alkyl group of said alkyl diazoacetate is a lower aliphatic alkyl.

Claim 12

The process according to claim 1, wherein the reaction is conducted in the presence of a solvent.

Claim 13

The process according to claim 11, wherein said solvent is an aromatic hydrocarbon.

Claim 14

A process for the production of an optically active alkyl chrysanthemate which comprises reacting 2,5-dimethyl-2,4-hexadiene with an alkyl diazoacetate in the presence of a copper complex coordinated with a chiral Schiff base at a temperature in the range of -50° C, said Schiff base having the formula: ##STR12## wherein C* is an asymmetric carbon atom, R 1 is selected from the group consisting of (a) alkyl groups whose carbon atom number is 1 - 10, and (b) aralkyl groups with or without alkoxy substituent(s), whose total carbon atom number is 7 - 20, R 2 is (a) 2-methoxyphenyl, (b) 2-ethoxyphenyl, (c) 2-isopropoxyphenyl, (d) 2-butoxyphenyl, (e) 2-octyloxyphenyl, (f) 2-benzyloxy-5-methylphenyl, (g) 2-butoxy-5-t-butylphenyl, (h) 5-t-butyl-2-octyloxyphenyl, (i) 4-butoxybiphenyl-3-yl, or (j) 2,5-dibutoxyphenyl, and Y is a hydrogen atom and wherein the molar ratio of the said copper complex to alkyl diazoacetate is in the range of 0.001 - 0.1.

Claim 15

A process for the production of an optically active alkyl chrysanthemate which comprises reacting 2,5-dimethyl-2,4-hexadiene with an alkyl diazoacetate in the presence of a copper complex coordinated with a chiral Schiff base at a temperature in the range of -50° C, said Schiff base having the formula: ##STR12## wherein C* is an asymmetric carbon atom, R 1 is selected from the group consisting of (a) alkyl groups whose carbon atom number is 1 - 10, and (b) aralkyl groups with or without alkoxy substituent(s), whose total carbon atom number is 7 - 20, R 2 is (a) 2-methoxyphenyl, (b) 2-ethoxyphenyl, (c) 2-isopropoxyphenyl, (d) 2-butoxyphenyl, (e) 2-octyloxyphenyl, (f) 2-benzyloxy-5-methylphenyl, (g) 2-butoxy-5-t-butylphenyl, (h) 5-t-butyl-2-octyloxyphenyl, (i) 4-butoxybiphenyl-3-yl, or (j) 2,5-dibutoxyphenyl, and Y is a hydrogen atom and wherein the molar ratio of the said copper complex to alkyl diazoacetate is in the range of 0.001 - 0.1.

Claim 16

A process for the production of an optically active alkyl chrysanthemate which comprises reacting 2,5-dimethyl-2,4-hexadiene with an alkyl diazoacetate in the presence of a copper complex coordinated with a chiral Schiff base at a temperature in the range of -50° C to 150° C, said chiral Schiff base being either an (R)- or (S)-enantiomer of the following: a. N-salicylidene-2-amino-1,1-di(2-isopropoxyphenyl)-3-phenyl-1-propanol, b. N-salicylidene-2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-3-phenyl-1-propanol, c. N-salicylidene-2-amino-1,1-di(2-methoxy-phenyl)-3-phenyl-1-propanol, d. N-salicylidene-2-amino-1,1-di(2-ethoxyphenyl)-3-phenyl-1-propanol, e. N-salicylidene-2-amino-1,1-di(2-butoxyphenyl)-3-phenyl-1-propanol, f. N-salicylidene-2-amino-1,1-di(2-octyloxyphenyl)-3-phenyl-1-propanol, g. N-salicylidene-2-amino-1,1-di(2-phenoxyphenyl)-3-phenyl-1-propanol, h. N-salicylidene-2-amino-1,1-di(2-benzyloxy-5-methylphenyl)-3-phenyl-1-propanol, i. N-salicylidene-2-amino-1,1-di(5-t-butyl-2-isopropoxyphenyl)-3-phenyl-1-propanol, j. N-salicylidene-2-amino-1,1-di(5-t-butyl-2-octyloxyphenyl)-3-phenyl-1-propanol, k. N-salicylidene-2-amino-1,1-di(4-butoxybiphenyl-3-yl)-3-phenyl-1-propanol, l. N-salicylidene-2-amino-1,1-di(2,5-dibutoxyphenyl)-3-3-phenyl-1-propanol, m. N-salicylidene-2-amino-1,1-di(2-isopropoxyphenyl)-3-(4-isopropoxyphenyl)-1-propanol, n. N-salicylidene-2-amino-1,1-di(5t-butyl-2-octyloxyphenyl)-3-(4-isopropoxyphenyl)-1-propanol, o. N-salicylidene-2-amino-1,1-di(2-butoxyphenyl)-3-cyclohexyl-1-propanol, p. N-salicylidene-2-amino-1,1-di(2-methoxyphenyl)-4-methyl-1-pentanol, q. N-salicylidene-2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-4-methyl-1-pentanol, r. N-salicylidene-2-amino-1,1-di(2-benzyloxy-5-t-butylphenyl)-4-methyl-1-pentanol, s. N-salicylidene-2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-1-propanol, t. N-salicylidene-2-amino-1,1-di(2-butoxyphenyl)-3-methyl-1-butanol, u. N-salicylidene-2-amino-1,1-di(2-butoxyphenyl)-1-propanol, v. N-(3,5-dibromosalicylidene)-2-amino-1,1-di(2-isopropoxyphenyl)-3-phenyl-1-propanol, w. N-(3-ethoxysalicylidene)-2-amino-1,1-di(2-isopropoxyphenyl)-3-phenyl-1-propanol, x. N-(2-hydroxy-1-naphthylmethylene)-2-amino-1,1-di(2-isopropoxyphenyl)-3-phenyl-1-propanol, or y. N-salicylidene-2-amino-1,1-di(4-butoxybiphenyl-3-yl)-1-propanol, and wherein the molar ratio of said copper complex to the alkyl diazoacetate is in the range of 0.001 - 0.1.

Claim 17

A process for the production of an optically active alkyl chrysanthemate which comprises reacting 2,5-dimethyl-2,4-hexadiene with an alkyl diazoacetate in the presence of a copper complex coordinated with a chiral Schiff base at a temperature in the range of -50° C to 150° C, said chiral Schiff base being either an (R)- or (S)-enantiomer of the following: a. N-salicylidene-2-amino-1,1-di(2-isopropoxyphenyl)-3-phenyl-1-propanol, b. N-salicylidene-2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-3-phenyl-1-propanol, c. N-salicylidene-2-amino-1,1-di(2-methoxy-phenyl)-3-phenyl-1-propanol, d. N-salicylidene-2-amino-1,1-di(2-ethoxyphenyl)-3-phenyl-1-propanol, e. N-salicylidene-2-amino-1,1-di(2-butoxyphenyl)-3-phenyl-1-propanol, f. N-salicylidene-2-amino-1,1-di(2-octyloxyphenyl)-3-phenyl-1-propanol, g. N-salicylidene-2-amino-1,1-di(2-phenoxyphenyl)-3-phenyl-1-propanol, h. N-salicylidene-2-amino-1,1-di(2-benzyloxy-5-methylphenyl)-3-phenyl-1-propanol, i. N-salicylidene-2-amino-1,1-di(5-t-butyl-2-isopropoxyphenyl)-3-phenyl-1-propanol, j. N-salicylidene-2-amino-1,1-di(5-t-butyl-2-octyloxyphenyl)-3-phenyl-1-propanol, k. N-salicylidene-2-amino-1,1-di(4-butoxybiphenyl-3-yl)-3-phenyl-1-propanol, l. N-salicylidene-2-amino-1,1-di(2,5-dibutoxyphenyl)-3-3-phenyl-1-propanol, m. N-salicylidene-2-amino-1,1-di(2-isopropoxyphenyl)-3-(4-isopropoxyphenyl)-1-propanol, n. N-salicylidene-2-amino-1,1-di(5t-butyl-2-octyloxyphenyl)-3-(4-isopropoxyphenyl)-1-propanol, o. N-salicylidene-2-amino-1,1-di(2-butoxyphenyl)-3-cyclohexyl-1-propanol, p. N-salicylidene-2-amino-1,1-di(2-methoxyphenyl)-4-methyl-1-pentanol, q. N-salicylidene-2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-4-methyl-1-pentanol, r. N-salicylidene-2-amino-1,1-di(2-benzyloxy-5-t-butylphenyl)-4-methyl-1-pentanol, s. N-salicylidene-2-amino-1,1-di(2-butoxy-5-t-butylphenyl)-1-propanol, t. N-salicylidene-2-amino-1,1-di(2-butoxyphenyl)-3-methyl-1-butanol, u. N-salicylidene-2-amino-1,1-di(2-butoxyphenyl)-1-propanol, v. N-(3,5-dibromosalicylidene)-2-amino-1,1-di(2-isopropoxyphenyl)-3-phenyl-1-propanol, w. N-(3-ethoxysalicylidene)-2-amino-1,1-di(2-isopropoxyphenyl)-3-phenyl-1-propanol, x. N-(2-hydroxy-1-naphthylmethylene)-2-amino-1,1-di(2-isopropoxyphenyl)-3-phenyl-1-propanol, or y. N-salicylidene-2-amino-1,1-di(4-butoxybiphenyl-3-yl)-1-propanol, and wherein the molar ratio of said copper complex to the alkyl diazoacetate is in the range of 0.001 - 0.1.

Claim 18

The process according to claim 14, wherein the alkyl group of said alkyl diazoacetate is a lower aliphatic alkyl.

Claim 19

The process according to claim 14, wherein the reaction is conducted in the presence of a solvent.

Claim 20

The process according to claim 16, wherein said solvent is an aromatic hydrocarbon.