217448-24-3Relevant academic research and scientific papers
Enantiospecific total synthesis of (-)-(E)16-epiaffinisine, (+)-(E)16-epinormacusine B, and (+)-dehydro-16-epiaffinisine as well as the stereocontrolled total synthesis of alkaloid G
Yu, Jianming,Wang, Tao,Wearing, Xiangyu Z.,Ma, Jun,Cook, James M.
, p. 5852 - 5859 (2007/10/03)
An efficient strategy is described for the total synthesis of the sarpagine-related indole alkaloids (-)-(E)16-epiaffinisine (1), (+)-(E)16-epinormacusine B (2), and (+)-dehydro-16-epiaffinisine (4). A key step employed the chemospecific and regiospecific
General approach for the synthesis of sarpagine indole alkaloids. Enantiospecific total synthesis of (+)-vellosimine, (+)-normacusine B, (-)-alkaloid Q3, (-)-panarine, (+)-Na-methylvellosimine, and (+)-Na-methyl-16-epipericyclivine
Yu, Jianming,Wang, Tao,Liu, Xiaoxiang,Deschamps, Jeffrey,Flippen-Anderson, Judith,Liao, Xuebin,Cook, James M.
, p. 7565 - 7581 (2007/10/03)
The first total synthesis of (+)-Na-methyl-16-epipericyclivine (9) was completed [from D-(+)-tryptophan methyl ester] in an overall yield of 42% (eight reaction vessels). The optical rotation [[α]D +22.8 (c 0.50, CHCl3)] obtained on this material confirmed that the reported optical rotation [[α]D 0 (c 0.50, CHCl 3)]47 was biogenetically unreasonable. The total syntheses of (+)-vellosimine, (+)-normacusine B, (-)-alkaloid Q3, (-)-panarine, and (+)-Na-methylvellosimine are also described. Moreover, a mixed sample (1:1) of synthetic (-)-panarine and natural (-)-panarine yielded only one set of signals in the 13C NMR; this indicated that the two compounds are identical and further confirmed the correct configuration of (+)-vellosimine, (+)-normacusine B, and (-)-alkaloid Q3. In this approach, the key templates, (-)-Na-H,N b-benzyltetracyclic ketone 15a and (-)-Na-methyl,N b-benzyltetracyclic ketone 43 were synthesized on multihundred gram scale by the asymmetric Pictet-Spengler reaction and a stereocontrolled Dieckmann cyclization via improved sequences. An intramolecular palladium (enolate-mediated) coupling reaction was employed to introduce the C(19)-C(20) E-ethylidene function in the sarpagine alkaloids for the first time in stereospecific fashion.
Stereocontrolled Total Synthesis of Alkaloid G via the Oxy-anion Cope Rearrangement and Improved Total Synthesis of (+)-Ajmaline
Wang, Tao,Xu, Qingge,Yu, Peng,Liu, Xiaoxiang,Cook, James M.
, p. 345 - 348 (2007/10/03)
(Matrix Presented) The oxy-anion Cope rearrangement followed by protonation of the enolate which resulted under conditions of kinetic control has been employed to generate the key asymmetric centers at C(15), C(16), and C(20) in alkaloid G (1) and (+)-ajm
Enantiospecific Total Synthesis of the Sarpagine Related Indole Alkaloids Talpinine and Talcarpine as Well as the Improved Total Synthesis of Alstonerine and Anhydromacrosalhine-methine via the Asymmetric Pictet-Spengler Reaction
Yu, Peng,Wang, Tao,Li, Jin,Cook, James M.
, p. 3173 - 3191 (2007/10/03)
The enantiospecific total synthesis of talpinine 1 and talcarpine 2 has been accomplished from D-(+)-tryptophan in 13 steps (11 reaction vessels) in 10% and 9.5% overall yields, respectively. Moreover, this synthetic approach has been employed for the improved synthesis of alstonerine 3 and anhydromacrosalhine-methine 4 in 12% and 14% overall yield, respectively. A convenient synthetic route for the enantiospecific, stereospecific preparation of the key intermediate (-)-Na-H, Nb-benzyl tetracyclic ketone 15a via the asymmetric Pictet-Spengler reaction on a multihundredgram scale has been developed. A diastereocontrolled (>30:1) anionic oxy-Cope rearrangement and the intramolecular rearrangement to form ring-E and an Nb-benzyl/Nb-methyl transfer reaction also served as key steps. This general approach can now be utilized for the synthesis of macroline/ sarpagine related indole alkaloids and their antipodes for biological screening.
General approach for the synthesis of ajmaline/sarpagine indole alkaloids: Enantiospecific total synthesis of (+)-ajmaline, alkaloid G, and norsuaveoline via the asymmetric Pictet-Spengler reaction
Li, Jin,Wang, Tao,Yu, Peng,Peterson,Weber,Soerens,Grubisha,Bennett,Cook
, p. 6998 - 7010 (2007/10/03)
A general approach (oxyanion-Cope strategy) for the synthesis of sarpagine/ajmaline indole alkaloids has been developed. (+)-Ajmaline 1 and alkaloid G 2 as well as norsuaveoline 3 have been synthesized from D-(+)-tryptophan in enantiospecific fashion via
The enantiospecific total synthesis of norsuaveoline
Wang, Tao,Yu, Peng,Li, Jin,Cook, James M.
, p. 8009 - 8012 (2007/10/03)
Norsuaveoline la has been synthesized enantiospecifically in 28% overall yield from commercially available D-(+)-tryptophan methyl ester via the asymmetric Pictet-Spengler reaction and a stereocontrolled oxy-anion Cope rearrangement as key steps.
