Über die Wirksamkeit von Substanzen aus dem Krotonöl

Towards the total synthesis of (-)-phorbol for novel anti-cancer studies

“…Since its isolation in 1935 phorbol (1.1) 4 has had a meteoric rise to fame as a tumor promoter via protein kinase C activation and is now a "house hold" tool for cancer biologists worldwide. 8a The issue with investigating and evaluating phorbol (1.1) and its derivatives, in a biological sense, is that these complex molecules are limited only to natural sources (i.e.…”

“…To date, 76 years after initial isolation 4 and 49 years after characterisation, 35 a concise and atom economical synthesis of phorbol or derivatives has yet to be achieved. Numerous efforts towards the synthesis of phorbol have been made to date.…”

“…1.185 and diene 1.178 utilising a chiral rhodium tetracarboxylate Rh 2 (R-PTAD) 4 developed by Davies et al This reaction proceeds via an in situ generated cyclopropane 1.186 followed by Cope rearrangement of the latter to afford 1.187.…”

“…4 followed by a Sonogashira coupling 69 utilising a protected propargyl alcohol. Compound 2.4 could then be derived from either direct cyclopropanation of 2.7 using dimethyldiazomethane or the employment of sulfur ylid chemistry for direct treatment of quinone 2.7.…”

“…3 In this view natural product chemistry (isolation and synthesis) in regards to drug discovery is an approach that has proven to be an effective and valuable source of inspiration from nature. One natural product, (+)-phorbol (1.1), 4 isolated in 1935 found significant attention by biologists and chemists alike due to its potent nature as a protein kinase C activator. Boehm successfully isolated phorbol from Croton tiglium, a member of the spurge family also called the Eurphorbiaceae family.…”