| abstract |
9-Thia-, 9-oxothia- and 9-dioxothia-11,12-secoprostaglandins of the formula II <IMAGE> are prepared, wherein A, R<4>, R<9> and R<10> are defined in Claim 1 and m is 0, 1 or 2. If n = 0, these compounds are obtained by reacting, in optional sequence, di-tert.-butyl malonate with two different appropriate halogeno-esters in order to introduce the two side chains. The reaction product obtained is a disubstituted malonic ester. By heating this ester in the presence of a strong acid, the corresponding substituted decarboxylated malonic acid derivative is obtained. This derivative is then reacted with bromine in the presence of mercury(II) oxide, whereby the carboxyl group is replaced by bromine. The resulting substituted bromo-ester is then reacted with the alkali metal salt of a mercaptan of the formula R<9>SH, and finally the ester group is hydrolysed. To prepare 9-oxothia- and 9-dioxothia-11,12-secoprostaglandins, the 9-thia-11,12-secoprostaglandins are oxidised. The compounds exhibit a prostaglandin-like activity and may be used for the treatment of skin diseases. |