Advanced Functionalization of Potential 9-Epi Precursors

For the sake of maximizing efficiency, the decision was made to prove the preceding question concurrently with the further functionalization of ring C. As reflected in our earlier studies involving 68, the appreciably hindered Cl 1-C12 double bond located in the five-membered ring was not expected to be more reactive than its counterpart in ring B in other settings. Indeed, dihydroxylation with osmium tetraoxide furnished 76, epoxidation of which led in a 

The next challenge in our pursuit of 9-epijatrophatrione (7) was the proper elimination of the elements of water from 82. However, 82 proved to be remarkably recalcitrant to dehydration under a wide variety of conditions.42 Companion studies involving 83 turned up one exciting lead. When heated with silver triflate or silver 

For a variety of reasons, many of which are not detailed herein, the wisdom of installing the 3-dicarbonyl array too soon was brought into question. Were this step relegated to the final stages of the synthesis, the built-in sensitivity arising from the potential for 13-elimination would be skirted. In this connection, the demise of 82 prompted the consideration of unsaturated precursors to 1 and 7 as viable synthetic candidates. 

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