Hydrindanone Synthesis: An Incisterol Model

Ethyl 1‐methyl‐2‐oxocyclohexanecarboxylate ( 1a ) and its homologue 1b were converted to hydroisobenzofuran acids 7 (via 6‐(butylsulfanyl)methylene] and epoxide derivatives), one of which furnished hexalone derivative 11 (via an intermediate diazomethyl ketone derivative). The above‐mentioned starting esters were converted to ethylene ketals, the free‐radical oxidations of which led to hydrobenzofuran acids. One of the latter led to a hydrindanone (via a diazomethyl ketone), whose further chemical elaboration yielded an incisterol model. A second hydrobenzofuran acid gave a cyclobutenone (via the diazomethyl ketone), which was transformed into a more‐stable cyclopentenone isomer by treatment with Lewis acid.