Bisdehydrodoisynolic acid

It is currently accepted that the theory of pseudocycles was elaborated to account for the estrogenic activity of compounds such as bisdehydrodoisynolic acid, allenestrol and diethylstilbestrol (Figure 16.3). 

Bisdehydrodoisynolic acid, effect on glycogen metabolism in rat diaphragm, X, 365... 

The yields in the various stages were very low, and this variant of the synthesis of (27) is therefore of no preparative importance and is used only for the correlation of the configurations between the series of allenolic and bisdehydrodoisynolic acids. 

The mechanism of the reaction of the vinyl carbinol (2) with cyclic 1,3-diketones has been discussed [1077]. New 1,3-dicarbonyl compounds have been condensed with this carbinol. Thus, the reaction with 2-chloro-l,3-cyclopentanedione led to an analog of 18-norestrone (1) with an aromatic ring C [1078]. The condensation of the isothiouronium salt of the vinyl carbinol (2) (see Scheme 38) with 4-acetoxy-2-methyl-l,3-cyclopentane-dione gave an unstable highly unsaturated compound (3) the catalytic hydrogenation and demethylation of which led to 8-isoestrone with an overall yield of 28% on the (2) [1079]. The reaction of the vinyl carbinol (2) with a, y-dimethyltetronic acid led to compound (4). Treatment with pal-ladized carbon and alkaline hydrolysis gave the keto ester (5) and the electrochemical reduction of this yielded racemic bisdehydrodoisynolic acid (6) [1080]. 

Startg. ( )-cis-ketoester electrolyzed at a lead cathode with 0.01 amp./sq.cm. current density in dioxane containing 20% sulfuric acid methyl ( )-cis-bisdehydrodoisynolate methyl ether. Y 70%. W. R. J. Simpson et al., Tetrah. Let. 1967, 3209. 

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