Homocubanecarboxylic acid

The most spectacular examples of the wide applicability of this method are the elegant syntheses of strained cubane- and homocubanecarboxylic acid derivatives,52 which have partially been reviewed (Houben-Weyl, Vol. 4/4, pp 94-119). 

Derivatives of homocubanecarboxylic acids are selectively available from bis(a-halo ketones) with the bishomocubane skeleton by protection of the carbonyl functions. Thus, 5-bromo-10,10-(ethylenedioxy)pentacyclo[5.3.0.02,6.03,9.05 8]decan-4-one and the corresponding 1,5-di-bromo derivative gave 9,9-(ethyIenedioxy)pentacyclo[4.3.0.02 5.03-8.04,7]nonane-4-carboxyIic acid (6a)61 and the 1-bromo derivative 6b,62 respectively, in good yields. 

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