Asymmetric synthesis of alkyl chrysanthemates
AssigneeSumitomo Chemical Company, Limited
InventorsTadatoshi Aratani, Shuzo Nakamura, Tsuneyuki Nagase, Yukio Yoneyoshi
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Abstract
Process for producing an optically active alkyl chrysanthemate by reacting 2,5-dimethyl-2,4-hexadiene with an alkyl diazoacetate in the presence of a copper complex coordinated with a particular Schiff base.
Claims17
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.degree. C to 150.degree. C, said Schiff base having the formula:
- ##STR7## wherein C* is an asymmetric carbon atom, R.sup.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.sup.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.
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.degree. C, said Schiff base having the formula:
- ##STR12## wherein C* is an asymmetric carbon atom, R.sup.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.sup.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.
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.degree. C to 150.degree. 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-propano l,
- 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-propa nol,
- i. N-salicylidene-2-amino-1,1-di(5-t-butyl-2-isopropoxyphenyl)-3-phenyl-1-pro panol,
- j. N-salicylidene-2-amino-1,1-di(5-t-butyl-2-octyloxyphenyl)-3-phenyl-1-propa nol,
- 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-isopropoxyph enyl)-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-pentano l,
- r. N-salicylidene-2-amino-1,1-di(2-benzyloxy-5-t-butylphenyl)-4-methyl-1-pent anol,
- 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-pro panol,
- x. N-(2-hydroxy-1-naphthylmethylene)-2-amino-1,1-di(2-isopropoxyphenyl)-3-phe nyl-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.
Dependencies are inferred from the claim text.