The four-step total synthesis of (−)-chaetominine

Abstract

The total synthesis of the alkaloid (-)-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 - epoxide ring-opening cyclization - 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.

Two New Indolyl Diketopiperazines, Trypostatins C and D from Aspergillus penicilliodes Speg.

“…Compounds 3 – 12 were 10 known indolyl diketopiperazines. They were identified as methyl( S )-{2-((3 R ,4a S ,9a R )-hydroxy-2-oxo-3-(4-oxoquinazolin-3(4 H )-yl)-2,3,4,4a, 9,9a-hexahydro-1 H -pyrido[ 2,3 - b ]indol-1-yl)propanoate}( 3 ), methyl( S )-{2-((3 R ,4a R , 9a S )-4a-hydroxy-2-oxo-3-(4-oxoquinazolin-3(4 H )-yl)-2,3,4,4a,9,9a-hexahydro-1 H - pyrido [ 2 , 3 ] indol-1-yl)propanoate}( 4 ) [ 16 , 17 ], chaetominine ( 5 ) [ 18 , 19 ], brevianamide F ( 6 ) [ 20 ], 6-methoxyspirotryprostatin B ( 7 ) [ 21 ], verruculogen ( 8 ) [ 22 ], fumitremorgin C ( 9 ) [ 23 ], cyclotryprostatin A ( 10 ), cyclotryprostatin B ( 11 ) and cyclotryprostatin C ( 12 ) [ 24 ], respectively, by comparison of their spectroscopic data with literature values, and single-crystal X-ray diffraction in the case of 5 . All of the isolates were obtained from A. penicilliodes for the first time.…”

Protecting-group-free synthesis of the bisindolylmaleimide GF109203X

“…21 Thus protecting-group-free synthesis has become a hot research topic in recent years. [22][23][24] Considering mono-N'-substituted BIMs such as 4-6 are important lead compounds for PKC inhibitions and further chemical biology studies, we believe it makes sense to develop a general synthesis [25][26][27][28][29] of them all, based on arcyriarubin A with a protecting-group-free strategy, which requires the direct mono-N'-alkylation of arcyriarubin A. In this paper, we report the mono-N'-alkylation of arcyriarubin A and its application to the protecting-group-free synthesis of GF109203X.…”

Improvement of chaetominine production by tryptophan feeding and medium optimization in submerged fermentation of Aspergillus fumigatus CY018

“…IFB-E015 in 2006 . Due to the unprecedented skeleton and its potential biological properties in treating cancer diseases, a number of efforts have been directed to the total synthesis of CHA in recent years (Snider and Wu 2007;Toumi et al 2008;Malgesini et al 2009;Peng et al 2014). More recently, there are some reports indicating that endophytic Aspergillus species are also shown to produce CHA.…”