The tricyclic hydroxy imidazolidinone was converted to chaetominine in seven steps in 22% overall yield. The key step was the construction of the delta-lactam by heating an amino ester with a catalytic amount of DMAP in toluene at reflux.
A total synthesis of the tripeptide alkaloid (−)‐chaetominine (1) was achieved in 9.3 % overall yield starting from commercially available D‐tryptophan methyl ester, based on a short and straightforward (nine steps) sequence. The early stage introduction (first step) of the quinazolinone moiety and the late stage introduction (penultimate step) of the hydroxy group allowed a synthetic strategy devoid
The total synthesis of the alkaloid (â)-chaetominine (1) has been achieved in four steps with an overall yield of 33.4%. Key features of our strategy include a one-pot cascade indole epoxidation â epoxide ring-opening cyclization â lactamization reaction sequence, and the use of a nitro group as a latent amino group for the one-pot construction of the quinazolinone ring. This constitutes a step economical, redox economical and protecting group-free total synthesis.
We demonstrated, for the first time, that on the basis of chemistry principles, the hexacyclic peptidyl alkaloid (â)-chaetominine (1) can be synthesized in a straightforward manner from L-Trp. The approach features the efficient generation of molecular complexity via a tandem C3/C14 syn-selective epoxidation (dr = 3â:â2)âannulative ring-opening reaction and a regioselective epimerization at C14. The successful production of (â)-chaetominine (1) from L-Trp could be helpful for revealing how the configuration of L-tryptophan becomes inverted in the biosynthetic pathway of (â)-chaetominine (1).
An efficient, asymmetric synthesis of the cytotoxic natural product chaetominine was achieved in 14 steps. The strategy employs a copper(I)-mediated cyclization reaction as a key step to install the abc-tricyclic ringsystem, which was further elaborated by diastereoselective oxidation and reduction reactions. This effort also documents the firstexample of an oxidative rearrangement yielding to homochiral
A straightforward total synthesis of the potent anticancer agent (-)-chaetominine is reported. Central to this synthesis was a biomimetic oxidative cyclization of a tryptophanyl-alanine dipeptide, which provided a fully elaborated 1,2,3,4-tetrahydropyrido[2,3-b]indole. Reduction of this intermediate followed by spontaneous cyclization and installation of the side chain provided synthetic chaetominine
报道了有效的抗癌药(-)-chaetominine的直接全合成。该合成的中心是色氨酸-丙氨酸二肽的仿生氧化环化,其提供了充分加工的1,2,3,4-四氢吡啶并[2,3- b ]吲哚。还原该中间体,然后自发环化并安装侧链,从商业上可得的廉价起始原料开始,以九个步骤的顺序以9%的总收率提供了合成的树脂胺。 生物碱-全合成-氧化环化-抗癌剂-肽