A Fast Entry to Furanoditerpenoid-Based Hedgehog Signaling Inhibitors: Identifying Essential Structural Features

New, small molecule Hedgehog (Hh) pathway inhibitors, such as the furanoditerpenoid taepeenin D, are of high medicinal importance. To establish key structure–activity relationships (SARs) for this lead, a synthetic sequence has been developed for the expedient preparation of several derivatives and their evaluation as Hh inhibitors exploiting its structural similarity to abietic acid. While C(14) substitution is not essential for biological activity, the presence of a hydrogen bond acceptor at C(6) and an intact benzofuran moiety are.