SYNTHETIC PLANT-GROWTH REGULATORS .3. PREPARATION OF FURTHER TRICYCLIC HELMINTHOSPORIC ACID ANALOGS WITH GIBBERELLIN-LIKE PROPERTIES

7-Methyl-7, 8-dihydro-4a, 7-methano-4aH-benzocycloheptene-2, 6(9H, 5H)-dione (6) was prepared and reduced to a 3: 7 mixture of the trans- and cis-decalin derived ketones (8) and (15). Each compound was further elaborated to the plant-growth-promoting acids (13), (14), (16) and (17). Dienone (5) was also reduced (NaBH4, hydrogenation) to a 7: 3 mixture of the cis- and trans-decalin derivatives (11) and (9). The stereochemistry of (11), and by inference (12), was determined by correlation with the known ketone (7). © 1979, CSIRO. All rights reserved.