Claims
- 1. A process for the preparation of a compound of the formula ##STR44## comprising reacting a compound of all possible stereoisomers and mixtures thereof of vinylsulfone nor-pyrethric compounds of the formula ##STR45## wherein R.sub.a is selected from the group consisting of tert.-butyl and phenyl substituted in position 2 and/or 6 with a functional group, n is 0, 1 or 2, R.sub.b is tert.-butyl and R is selected from the group consisting of hydrogen, alkyl of 1 to 8 carbon atoms and the residue of an alcohol used in pyrethrinoid products with the reducing agent capable of producing SO.sub.2.sup.- to obtain the formula ##STR46## in which R.sub.a, R.sub.b and R have the above definitions which is isolated, if desired, or is decomposed spontaneously to give the corresponding compound of the formula ##STR47## in which R.sub.b and R retain the above definition.
- 2. The process of claim 1 wherein the reducing agent is an anion selected from the group consisting of S.sub.2 O.sub.4 .sup.-, HS.sup.-, SO.sub.3.sup.-, I.sup.-, SCN.sup.-, CN.sup.-, alk.sub.4 S.sup.-, (alk.sub.5).sub.3 Si.sup.- or (alk.sub.6).sub.3 Sn.sup.- and alk.sub.4, alk.sub.5 and alk.sub.6 are alkyl of 1 to 8 carbon atoms.
- 3. The process of claim 1 wherein the reducing agent is a compound capable of producing HSO.sub.2.sup.- or SO.sub.2.sup.- anions.
- 4. The process of claim 2 wherein the anion is S.sub.2 O.sub.4.sup.-.
- 5. The process of claim 1 wherein the reducing agent is Na.sub.2 S.sub.2 O.sub.4 in a mixture of water and an organic solvent.
- 6. The process of claim 5 wherein there is present a phase transfer agent.
- 7. The process of claim 1 wherein R.sub.a is tert.-butyl.
Priority Claims (1)
Number |
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88 06934 |
May 1988 |
FRX |
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PRIOR APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 499,016 filed Mar. 26, 1990, now abandoned which is a division of U.S. patent application Ser. No. 356,747 filed May 24, 1989, now abandoned.
Non-Patent Literature Citations (2)
Entry |
Ramos et al, "Chirality and Crop Protection", Angewandte Chemie vol. 30, No. 10, Oct. 1991, pp. 1193 & 1212. |
Babin et al, "A New Way . . . ", J. Org. Chem, 1992 vol. 57, 1992 pp. 548-589. |
Divisions (1)
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Date |
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Parent |
356747 |
May 1989 |
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Continuations (1)
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Number |
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Parent |
499016 |
Mar 1990 |
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