A drug of two halves: New artificial compounds composed of a macrosphelidecore skeleton and an epothilone side chain were designed and synthesized. These compounds were more potent inducers of apoptosis than the parent natural‐type macrosphelides.
A new synthetic route for macrosphelides A, B, and E based on ring-closing metathesis (RCM) was established. The substrates for RCM could be synthesized starting from commercially available chiral materials, methyl (S)-lactate and methyl (S)- or (R)-3-hydroxybutyrate, in good overall yields. In the investigation of the key RCM step, it was found that the steric factor around the reaction site significantly affected the reaction rate of macrocyclization. A detailed account regarding this synthetic study is described herein.
Synthesis of Macrosphelides with a Thiazole Side Chain: New Antitumor Candidates Having Apoptosis-Inducing Property
Hybrid compounds of macrosphelides and epothilones, both of which are natural macrolides having a 16-membered skeleton, were designed and synthesized using a ring-closing metathesis (RCM) strategy. Some of these hybrids were found to exhibit notable apoptosis-inducing activity against human lymphoma cells with higher potency than parent natural macrosphelides, and to be a promising lead compound for development of a new antitumor agent.
Total synthesis of 2-nor-macrosphelides, a 15-membered analogue of 16-membered natural macrosphelides, is described. The synthesis was accomplished starting from methyl L-(+)-lactate as a sole chiral source with a high efficiency.