Synthesis of polycyclic compounds related to steroids Communication XXII. Stereochemistry of polycyclic compounds. II. Monoesters of the cis and trans forms of 1-methyl-1,2-cyciahexanedicarboxylic and 1-methyl-4-cyclohexene-1,2-dicarboxylic acids, and their reactions

Summary

• 1. The crystalline cis-monoester VII and the liquid cis-monoester IX have been prepared from the cisanhydride VI, the cis-dicarboxylic acid VIII, and the ester of this acid (X). By hydrogenation of these monoesters the corresponding saturated cis-monoesters XI and XIII have been prepared, and the structures of these have been proved by converting them into the known cis-carboxymethyl cyclohexaneacetic acids XVI and XX.

• 2. It has been found that, when the unsaturated cis-monoesters VII and IX and their acid chlorides XIV and XVIIII react with aniline at 30°, the same product, the phenylimide XXIII, is obtained in all cases. Only under very mild reaction conditions (0°) was it possible to isolate the corresponding cis-anilides (XXIV and XXV). re, lily converted when heated with phosphoryl chloride into the phenylimide XXIII.

• 3. In the case of the cis-acid chlorides XVII and XXI, lengthening of the carbon chain occurs with partial conversion to the corresponding trans-acids XXXVIII and XXXIX. The secondary carboxy group enters into the Arndt-Eistert reaction considerably mote readily than the tertiary carboxyl group.

• 4. The tracts-monoester XXV III, hydrogenation of which gives the saturated trans -monoester XXIX, was prepared in satisfactory yield from the trans-anhydride XXVI and the trans-diester XXVII.

• 5. The monoester and acid chlorides of the trans series readily give stable anilides, and they enter the Arndt-Eistert reaction considerably more readily than do the monoesters of the cis series.