Claims
- 1. A process for the preparation of a compound of the formula ##STR13## wherein the wavy line indicates the existence of two isomers, and reacting a compound of the formula ##STR14## wherein R is selected from the group consisting of hydrogen, acyl of an organic carboxylic acid of 1 to 8 carbon atoms, allyloxycarbonyl, alkyoxycarbonyl and aralkoxycarbonyl of up to 8 carbon atoms, and alkyl sulfonyl and arylsulfonyl of up to 8 carbon atoms with a bromination agent or chlorination agent and a formyloxylation agent in an acid medium to obtain a compound of the formula ##STR15## wherein R is defined as above and Hal is bromine or chlorine, reacting the latter with acetone in the presence of a strong acid to obtain a compound of the formula ##STR16## and reacting the latter with a dehalogenation agent to obtain a compound of formula I ##STR17## wherein R is selected from the group consisting of hydrogen, acyl of an organic carboxylic acid of 1 to 8 carbon atoms, allyloxycarbonyl, alkyoxycarbonyl and aralkoxycarbonyl of up to 8 carbon atoms, and alkylsulfonyl and arylsulfonyl of up to 8 carbon atoms reacting the latter with butanal in the presence of a strong acid catalyst to obtain a compound of the formula ##STR18## wherein R has the above definition and subjecting the latter to a solvolysis in a basic medium to form a compound of formula V.
- 2. The process of claim 1 wherein the chlorination or bromination agent is selected from the group consisting of N-chloro-acetamide, N-bromo-acetamide, N-chloro or bromo-succinimide, N-chloro- or bromo-phthalimide, N,N-dichloro-dimethylhydantoin, N,N-dibromo-dimethyl-hydantoin, tert.-butyl-hypochlorite and tert.-butyl-hypobromite, the formyloxylation agent is formic acid or dimethylformamide, the strong acid for ketalization is perchloric acid or fluoroboric acid, and the ketalization is effected in the presence of a dehydrating agent and the dehalogenation is effected with tributyltin hydride in the presence of a radical reaction initiator.
- 3. The process of claim 1 wherein R is acetyl.
- 4. The process of claim 1 wherein the strong acid catalyst is perchloric acid and the solvolysis is an alcoholysis effected with sodium methanolate or potassium methanolate in dioxane.
- 5. A process for the preparation of a compound of the formula ##STR19## comprising reacting a compound of the formula ##STR20## wherein R has the definition below with a bromination agent or chlorination agent and a formyloxylation agent in an acid medium to obtain a compound of the formula ##STR21## wherein R is defined as above and Hal is bromine or chlorine, reacting the latter with acetone in the presence of a strong acid to obtain a compound of the formula ##STR22## and reacting the latter with a dehalogenation agent to obtain a compound of formula I ##STR23## wherein R is selected from the group consisting of hydrogen, acyl of an organic carboxylic acid of 1 to 8 carbon atoms, allyloxycarbonyl, alkyoxycarbonyl and aralkoxycarbonyl of up to 8 carbon atoms, and alkylsulfonyl and arylsulfonyl of up to 8 carbon atoms subjecting the latter compound to a solvolysis in a basic medium to obtain a compound of formula VIII.
- 6. The process of claim 5 wherein R is acetyl.
- 7. The process of claim 5 wherein the solvolysis is effected with sodium methanolate or potassium methanolate in dioxane.
Priority Claims (1)
Number |
Date |
Country |
Kind |
91 04339 |
Apr 1991 |
FRX |
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PRIOR APPLICATION
This application is a division of U.S. patent application Ser. No. 856,546 filed Mar. 24, 1992, now abandoned.
US Referenced Citations (5)
Foreign Referenced Citations (6)
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Feb 1986 |
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3143757 |
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Divisions (1)
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Number |
Date |
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Parent |
856546 |
Mar 1992 |
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