Co-reporter:Xue Yang, Bin Cheng, Hang Cheng, Liang Xu, Jian-Li Wang
Chinese Chemical Letters 2017 Volume 28, Issue 8(Volume 28, Issue 8) pp:
Publication Date(Web):1 August 2017
DOI:10.1016/j.cclet.2017.03.032
A model study leading to the preparation of the unique tricyclo [6.2.1.0] undecane BCD ring systems of aconitine is described. The synthesis features an unprecedented diastereoselective oxidative dearomatization/dimerization/retro-DA/IMDA cascade reaction and a highly efficient Wagner-Meerwein rearrangement.Download high-res image (136KB)Download full-size imageA model study leading to the preparation of the unique tricyclo[6.2.1.0]undecane BCD ring systems of aconitine is described. The synthesis features an unprecedented diastereoselective oxidative dearomatization/dimerization/retro-DA/IMDA cascade reaction and a highly efficient Wagner-Meerwein rearrangement.
Co-reporter:Dai-Hui Tang, Ding Ma, Hang Cheng, Yong-Li Li and Liang Xu
Organic & Biomolecular Chemistry 2016 vol. 14(Issue 9) pp:2716-2722
Publication Date(Web):25 Jan 2016
DOI:10.1039/C6OB00053C
A bio-inspired synthetic strategy for the efficient construction of the structurally complex azapentacyclic ABEFG ring systems of Spiraea atisine-type diterpenoid alkaloids bearing a characteristic internal carbinolamine ether linkage between C(7) and C(20) has been successfully developed. The highly bridged azapentacyclic core structure was constructed rapidly from a readily prepared trans-6,6-bicyclic AB ring precursor through a 14-step sequence. Highlights of the synthesis include a straightforward formal lactone migration from the tricyclic γ-lactone unit of naturally occurring spiramilactone E, and an efficient biomimetic synthesis of the azapentacyclic ABEFG ring systems of spiramines C and D from the corresponding tetracyclic subunits of spiraminol and spiramilactone B.
Co-reporter:Min-Li Jiang, Yin-Juan Meng, Wei-Yan Xiong, Liang Xu
Tetrahedron Letters 2016 Volume 57(Issue 14) pp:1610-1612
Publication Date(Web):6 April 2016
DOI:10.1016/j.tetlet.2016.02.110
•A regio- and stereoselective ring opening of aziridine was developed.•A key free radical cyclization reaction is used to construct functionalized ring B.•A functionalized ABEF tetracyclic ring system of racemulosine was constructed.A continued effort to synthesis of functionalized ABEF tetracyclic ring system of structurally complex C20-diterpenoid alkaloid racemulosine from previously reported tetracyclic aziridine intermediate 3 was described. The synthesis features a regio- and stereoselective ring opening of aziridine and a challenging free radical cyclization reaction to construct functionalized ring B, which could provide a good basis for total synthesis of racemulosine.
Co-reporter:Yong-Li Li, Meng-Chen Liu, Yin-Juan Meng, Liang Xu
Tetrahedron 2016 Volume 72(Issue 23) pp:3171-3176
Publication Date(Web):9 June 2016
DOI:10.1016/j.tet.2016.04.027
Two new approaches for the construction the ABF ring systems of 7,17-seco-type C19-diterpenoid alkaloids have been successfully developed by using free radical cyclization and intramolecular nitrile oxide cycloaddition, respectively, as the key steps. Both methods would probably provide alternative strategies for the elaboration of AEF-rings in the total synthesis of 7,17-seco-type C19-diterpenoid alkaloids based on our previously prepared BCD ring systems.
Co-reporter:Hang Cheng;Fan-Hao Zeng;Xue Yang;Yin-Juan Meng; Liang Xu; Feng-Peng Wang
Angewandte Chemie 2016 Volume 128( Issue 1) pp:400-404
Publication Date(Web):
DOI:10.1002/ange.201508996
Abstract
The first total syntheses of the architecturally complex atisane-type diterpenes and biogenetically related atisine-type diterpenoid alkaloids (±)-spiramilactone B, (±)-spiraminol, (±)-dihydroajaconine, and (±)-spiramines C and D are reported. Highlights of the synthesis include a late-stage biomimetic transformation of spiramilactone B, a facile formal lactone migration from the pentacyclic skeleton of spiramilactone E, a highly efficient and diastereoselective 1,7-enyne cycloisomerization to construct the functionalized tetracyclic atisane skeleton, and a tandem retro-Diels–Alder/intramolecular Diels–Alder sequence to achieve the tricyclo[6.2.2.0] ring system.
Co-reporter:Hang Cheng;Fan-Hao Zeng;Xue Yang;Yin-Juan Meng; Liang Xu; Feng-Peng Wang
Angewandte Chemie International Edition 2016 Volume 55( Issue 1) pp:392-396
Publication Date(Web):
DOI:10.1002/anie.201508996
Abstract
The first total syntheses of the architecturally complex atisane-type diterpenes and biogenetically related atisine-type diterpenoid alkaloids (±)-spiramilactone B, (±)-spiraminol, (±)-dihydroajaconine, and (±)-spiramines C and D are reported. Highlights of the synthesis include a late-stage biomimetic transformation of spiramilactone B, a facile formal lactone migration from the pentacyclic skeleton of spiramilactone E, a highly efficient and diastereoselective 1,7-enyne cycloisomerization to construct the functionalized tetracyclic atisane skeleton, and a tandem retro-Diels–Alder/intramolecular Diels–Alder sequence to achieve the tricyclo[6.2.2.0] ring system.
Co-reporter:Ding Ma, Hang Cheng, Chunmei Huang, Liang Xu
Tetrahedron Letters 2015 Volume 56(Issue 19) pp:2492-2495
Publication Date(Web):6 May 2015
DOI:10.1016/j.tetlet.2015.03.097
An efficient synthetic strategy for the direct and rapid construction of the [6-5-7] ACD azatricyclic ring system of numerous calyciphylline A-type alkaloids has been successfully developed. The synthesis featuring an unprecedented protonic acid promoted intramolecular [3+2] cycloaddition via a nonstabilized azomethine ylide generated by desilylation of N-(trimethylsilyl)methyl iminium salt bearing enolizable hydrogens.
Co-reporter:Wei Zhang, Hang Cheng, Yongli Li, Chunmei Huang, Liang Xu
Tetrahedron 2015 Volume 71(Issue 30) pp:4967-4973
Publication Date(Web):29 July 2015
DOI:10.1016/j.tet.2015.05.078
A base-promoted 1,5-ester shifting rearrangement reaction has been developed to access unusually functionalized seven-membered ring precursors, which could be further successfully transformed into bicyclo[3.2.1]octenes by directly closing one-carbon bridge via a key carbocation-based cyclization, providing a new and efficient route to the core of many natural products and their analogs.
Co-reporter:Jie Li, Liang Xu
Tetrahedron 2015 Volume 71(Issue 19) pp:2858-2862
Publication Date(Web):13 May 2015
DOI:10.1016/j.tet.2015.03.067
A series of novel chiral 3,4,5,6-tetrahydropyrimidinium salts, the precursor of N-heterocyclic carbene ligands, were designed and synthesized from (1S, 3S)-1,3-diphenyl-1,3-propanediamine. In situ prepared corresponding carbenes were tested in asymmetric copper-catalysed 1,4 conjugate addition of Grignard reagents to 3-methylcyclohexenone, allowing enantiomeric excesses of up to 87% to be achieved.
Co-reporter:Hang Cheng, Fan-Hao Zeng, Ding Ma, Min-Li Jiang, Liang Xu, and Feng-Peng Wang
Organic Letters 2014 Volume 16(Issue 9) pp:2299-2301
Publication Date(Web):April 4, 2014
DOI:10.1021/ol500726x
A synthetic strategy for the modeling construction of the highly bridged azatetracyclic ABEF ring system of numerous lycoctonine-type C19-diterpenoid alkaloids bearing a characteristic oxygenated quaternary center at C-7 has been successfully developed. The tetracyclic core was constructed rapidly from a readily prepared 6,7-bicyclic AB ring precursor through a 13-step sequence via an advanced tetracyclic N,O-acetal intermediate, which belong to another core structure of natural 7,17-seco-type alkaloids. The key step involves an SmI2-promoted intramolecular radical coupling reaction of an N,O-acetal with a carbonyl group, mimicking a plausible biogenetic transformation.
Co-reporter:Ru-Huai Mei, Zhi-Gang Liu, Hang Cheng, Liang Xu, and Feng-Peng Wang
Organic Letters 2013 Volume 15(Issue 9) pp:2206-2209
Publication Date(Web):April 15, 2013
DOI:10.1021/ol400755x
The functionalized A/E/F ring system of C20-diterpenoid alkaloid racemulsonine has been efficiently synthesized. The Key steps involved a diastereoselective Au(I)-catalyzed annulation to form cis-fused cyclopentene and a PIDA promoted transannular aziridination of primary amine followed by regio- and stereoselective ring cleavage of bridged aziridine.
Co-reporter:Zhi-Gang Liu, Hang Cheng, Meng-Jia Ge, Liang Xu, Feng-Peng Wang
Tetrahedron 2013 69(26) pp: 5431-5437
Publication Date(Web):
DOI:10.1016/j.tet.2013.04.102
Co-reporter:Hang Cheng, Liang Xu, De-Lin Chen, Qiao-Hong Chen, Feng-Peng Wang
Tetrahedron 2012 68(4) pp: 1171-1176
Publication Date(Web):
DOI:10.1016/j.tet.2011.11.063
Co-reporter:Zhi-Gang Liu, Liang Xu, Qiao-Hong Chen, Feng-Peng Wang
Tetrahedron 2012 68(1) pp: 159-165
Publication Date(Web):
DOI:10.1016/j.tet.2011.10.073
Co-reporter:Dai-Hui Tang, Ding Ma, Hang Cheng, Yong-Li Li and Liang Xu
Organic & Biomolecular Chemistry 2016 - vol. 14(Issue 9) pp:NaN2722-2722
Publication Date(Web):2016/01/25
DOI:10.1039/C6OB00053C
A bio-inspired synthetic strategy for the efficient construction of the structurally complex azapentacyclic ABEFG ring systems of Spiraea atisine-type diterpenoid alkaloids bearing a characteristic internal carbinolamine ether linkage between C(7) and C(20) has been successfully developed. The highly bridged azapentacyclic core structure was constructed rapidly from a readily prepared trans-6,6-bicyclic AB ring precursor through a 14-step sequence. Highlights of the synthesis include a straightforward formal lactone migration from the tricyclic γ-lactone unit of naturally occurring spiramilactone E, and an efficient biomimetic synthesis of the azapentacyclic ABEFG ring systems of spiramines C and D from the corresponding tetracyclic subunits of spiraminol and spiramilactone B.
