Process for preparing organic compounds
Process for preparing a compound of the formula (I) in which R 1 and R 2 are each independently H, C 1 -C 8 -alkyl, halogen, polyhalo-C 1 -C 8 -alkoxy, polyhalo-C 1 -C 8 -alkyl, C 1 -C 8 -alkoxy, C 1 -C 8 -alkoxy-C 1 -C 8 -alkyl, or C 1 -C 8 -alkoxy-C 1 -C 8 -alkoxy, where R 1 and R 2 are not both H, and R 3 is C 1 -C 8 -alkyl, which is characterized in that a) a compound of the formula (II) in which R 1 and R 2 are each as defined above and X is Br, I, triflate, toyslate or mesylate is reacted with prop-2-yn-1-ol to give the compound of the formula (III), b) the compound of the formula (III) is reacted with an alkyl-metal compound in which “alkyl” is as defined above for R 3 to give a compound of the formula (I).
1. Process for preparing a compound of the formula I
in which
R 1 is a linear or branched C 1 -C 8 -alkoxy-C 1 -C 8 -alkoxy radical,
R 2 is a linear or branched C 1 -C 8 -alkyl radical or a linear or branched C 1 -C 8 -alkoxy radical, and
R 3 is isopropyl,
which is characterized in that
a) a compound of the formula II
in which R 1 and R 2 are each as defined above and X is Br, I, triflate, toyslate or mesylate is reacted with prop-2-yn-1-ol to give the compound of the formula III
b) the compound of the formula III is reacted with an alkyl-metal compound in which “alkyl” is as defined above for R 3 to give a compound of the formula I.
2. Process according to claim 1 , wherein R 1 is methoxy- or ethoxy-C 1 -C 4 -alkoxy, and R 2 is methyl, ethyl, methoxy or ethoxy.
3. Process according to claim 1 , wherein R 1 is 3-methoxypropoxy or 4-methoxybutoxy and R 2 is methyl or methoxy.
4. Process according to claim 1 , wherein R 1 is 3-methoxypropoxy and R 2 is methoxy.
5. Compound of the formula III
in which R 1 is methoxypropoxy, and R 2 is methoxy.
6. Process according to claim 1 , wherein the compound of the formula (I) prepared according to claim 1 is converted by asymmetric hydrogenation to a compound of the formula D
in which
R 1 is a linear or branched C 1 -C 8 -alkoxy-C 1 -C 8 -alkoxy radical,
R 2 is a linear or branched C 1 -C 8 -alkyl radical or a linear or branched C 1 -C 8 -alkoxy radical, and
R 3 is isopropyl,
the compound of the formula D is converted by halogenation to a compound of the formula B
where Y is Cl, Br or I,
the compound of the formula B is reacted with a compound of the formula C,
in which R 4 is C 1 -C 8 -alkyl, R 5 is C 1 -C 8 -alkyl or C 1 -C 8 -alkoxy, R 6 is C 1 -C 8 -alkyl, or R 5 and R 6 together are optionally C 1 -C 4 -alkyl-, phenyl- or benzyl-substituted tetramethylene, pentamethylene, 3-oxa-1,5-pentylene or —CH 2 CH 2 O—C(O)—, and Z is Cl, Br or I,
in the presence of an alkali metal or alkaline earth metal, to give a compound of the formula A
7. Process according to claim 6 , wherein R 1 is methoxy- or ethoxy-C 1 -C 4 -alkoxy, and R 2 is methyl, ethyl, methoxy or ethoxy.
8. Process according to claim 6 , wherein R 1 is 3-methoxypropoxy or 4-methoxybutoxy and R 2 is methyl or methoxy.
9. Process according to claim 6 , wherein R 1 is 3-methoxypropoxy and R 2 is methoxy.