Claims
- 1. A process for the preparation of a compound of the formula ##STR29## wherein R.sub.1 is acyl of 1 to 8 carbon atoms comprising reacting a compound of the formula ##STR30## wherein Hal is chlorine or bromine, R is selected from the group consisting of alkyl of 1 to 6 carbon atoms, aralkyl of 7 to 15 carbon atoms and a silylated group, K is a protective group selected from the group consisting of ##STR31## n is 2 or 3 and the wavy lines mean the groups may have either isomer form or are mixtures thereof in an alkaline medium with an alkaline sulfinate of the formula
- R.sub.2 --SO.sub.2 --Q
- wherein R.sub.2 is selected from the group consisting of methyl, phenyl, tolyl or xylyl and Q is an alkali metal in the presence of a base to obtain after saponification and decarboxylation a compound of the formula ##STR32## wherein K and R.sub.2 are defined as above, subjecting the latter to the action of formaldehyde in the presence of a base to obtain a compound of the formula ##STR33## subjecting the latter to the action of an epoxidation agent in an alkaline medium to obtain a compound of the formula ##STR34## opening the epoxide function of the compound of formula XI in a basic medium and in the presence of R.sub.1 O.sup.- ions, in which R.sub.1 is defined as above to obtain a compound of the formula ##STR35## the protected 3-oxo function of which is deprotected to obtain the compound of formula A.
- 2. The process of claim 1 wherein the alkaline sulfinate is sodium toluenesulfinate and the opening of the epoxide is carried out in the presence of acetate ions.
Priority Claims (1)
Number |
Date |
Country |
Kind |
91 06202 |
May 1991 |
FRX |
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PRIOR APPLICATIONS
This application is a division of U.S. Ser. No. 145,890 filed Oct. 29, 1993, now U.S. Pat. No. 5,401,864, which is a division of U.S. patent application Ser. No. 971,189 filed Nov. 4, 1992, now U.S. Pat. No. 5,294,704, which is a division of U.S. patent application Ser. No. 885,150 filed May 18, 1992, now U.S. Pat. No. 5,187,273.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4309423 |
Biollaz |
Jan 1982 |
|
Non-Patent Literature Citations (1)
Entry |
Greene et al, Protective Groups in Organic Synthesis, 2nd edition, 1991, pp. 202-205. |
Divisions (3)
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Number |
Date |
Country |
Parent |
145890 |
Oct 1993 |
|
Parent |
971189 |
Nov 1992 |
|
Parent |
885150 |
May 1992 |
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