Acetylene derivatives

Summary

• 1. Heating of 2-methoxy-1,3-butadiene (I) with 2,4-dimethyl-2-cyclopenten-1-one (V) yields as the main product of methoxytetrahydroindanone(VI), but there is formed in small amount also the isomeric methoxytetrahydroindanone (VIa). On condensation of the mixture (VI + VIa) with acetylene in liquid ammonia and subsequent hydrolysis of the product, there are obtained two crystalline acetylenic hydroxy ketones, 1-ethynyltetrahydro-1-hydroxy-3,7a-dimethyl-5(4H)-indanone (VIII, and 1-ethynyltetrahydro-1-hydroxy-0-7a-dimethyl-6(5H)-indanone (IX). A number of derivatives were prepared from the latter — the vinylhydroxy ketone (XVI), the dienone (XVII) the anhydride(XVII), and the keto acid (XIX).

• 2. By condensation of the previously described dienone X with 2-methyl-2-cyclopenten-1-one (XI), with 2-methyl-2-cyclohexen-1-one (II), and with p-quinone (XII), the steroid tetracyclic ketones (XIII, XIV, and XV) having a five-membered B ring have been prepared.

• 3. By condensation of hexahydro-5-methoxy-3,7a-dimethyl-1-indanone (XX) with acetylene in liquid ammonia, 1-ethynylhexahydro-5-methoxy-3,7a-dimethyl-1-indanol (XXI) was prepared, and from this there were obtained the compounds hexahydro-5-methoxy-3,7a-dimethyl-1-vinyl-1-indanol (XXIII) and 3a,4,5,6,7,7a-hexahydro-6-methoxy-1,3a-dimethyl-3-vinylindene (XXIV).

• 4. By condensation of the diene (XXIV) with maleic anhydride, with p-quinone, and with 2-methyl-2-cyclohexen-1-one there were obtained the tricyclic anhydride (XXV), the acid (XXVI), and the tetracyclic methoxy ketones (XXVII and XXVIII).