Linclau and co-workers reported that crude 3 could only be subjected to the Favorskii rearrangement conditions after being refluxed in water to hydrolyse any methyl ketals present. As our method avoids the formation of any methyl ketals, crude 3 could undergo the desired Favorskii rearrangement without the water hydrolysis step to give crude 4. To allow for facile purification, 4 was then converted to the methyl ester using an acidic methanol solution to give the final compound 1 in 20% yield over three steps from 2. Although this represents a lower overall yield than the 54% achieved by Linclau and coworkers, considering the high conversion and NMR yield for the formation of 3 through [2+2] cycloaddition we hypothesise this is due to difficulties in precipitating 4 on a much smaller scale. Having completed the synthesis of 1, our attention turned to the photocatalytic functionalization of cubane using cubane carboxylic acid 5 as a convenient cubyl radical precursor. First, 5 was synthesised via hydrolysis of 1 in 50% yield, with 44% of the unreacted diester being recovered (Scheme 3A). Then, 5 was subjected to a photocatalytic decarboxylation procedure known to work efficiently with other tertiary carboxylic acids such as 1-adamantylcarboxyclic acid; 18 however, only trace amounts of the desired product, 6, was observed (Scheme 3B).