Large-Scale Synthesis and Modifications of Bicyclo[1.1.1]pentane-1,3-dicarboxylic Acid (BCP).

In flow photochemical addition of propellane to diacetyl allowed construction of the bicyclo[1.1.1]pentane (BCP) core in a 1 kg scale within 1 day. Haloform reaction of the formed diketone in batch afforded bicyclo[1.1.1]pentane-1,3-dicarboxylic acid in a multigram amount. Representative gram scale transformations of the diacid were also performed to obtain various BCP-containing building blocks-alcohols, acids, amines, trifluoroborates, amino acids, etc.-for medicinal chemistry.