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Thomas J. Maimone

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Name: Maimone, Thomas
Organization: University of California?Berkeley , USA
Department: Department of Chemistry
Title: (PhD)

TOPICS

Navigating the Chiral Pool in the Total Synthesis of Complex Terpene Natural Products
Co-reporter:Zachary G. Brill, Matthew L. Condakes, Chi P. Ting, and Thomas J. Maimone
Chemical Reviews September 27, 2017 Volume 117(Issue 18) pp:11753-11753
Publication Date(Web):March 15, 2017
DOI:10.1021/acs.chemrev.6b00834
The pool of abundant chiral terpene building blocks (i.e., “chiral pool terpenes”) has long served as a starting point for the chemical synthesis of complex natural products, including many terpenes themselves. As inexpensive and versatile starting materials, such compounds continue to influence modern synthetic chemistry. This review highlights 21st century terpene total syntheses which themselves use small, terpene-derived materials as building blocks. An outlook to the future of research in this area is highlighted as well.
Traversing Biosynthetic Carbocation Landscapes in the Total Synthesis of Andrastin and Terretonin Meroterpenes
Co-reporter:Dr. Gong Xu;Masha Elkin; Dr. Dean J. Tantillo; Dr. Timothy R. Newhouse; Dr. Thomas J. Maimone
Angewandte Chemie International Edition 2017 Volume 56(Issue 41) pp:12498-12502
Publication Date(Web):2017/10/02
DOI:10.1002/anie.201705654
AbstractMeroterpenes derived from dimethylorsellinic acid (DMOA) and farnesyl pyrophosphate have attracted much biosynthetic attention, yet only recently have synthetic solutions to any family members appeared. A key point of divergence in DMOA-derived meroterpene biosynthesis is the protoaustinoid A carbocation, which can be diverted to either the berkeleyone, andrastin, or terretonin structural classes by cyclase-controlled rearrangement pathways. Shown herein is that the protoaustinoid bicyclo[3.3.1]nonane nucleus can be reverted to either andrastin or terretonin ring systems under abiotic reaction conditions. The first total syntheses of members of these natural product families are reported as their racemates.
Enantioselective synthesis of an ophiobolin sesterterpene via a programmed radical cascade
Co-reporter:Zachary G. Brill;Huck K. Grover
Science 2016 Vol 352(6289) pp:1078-1082
Publication Date(Web):27 May 2016
DOI:10.1126/science.aaf6742

A radical route to ophiobolin rings

Chemical ring-closing cascades resemble molecular yoga. One reactive site on a linear precursor can pull the whole molecule into a remarkably complex polycyclic arrangement. Cyclase enzymes rely on substantial internal scaffolding to guide this process during the biosynthesis of the ophiobolin sesterterpene frameworks, which comprise two pentagons sharing edges with an octagon. Brill et al. now show that the same motif is accessible abiotically by tweaking the cascade mechanism to rely on neutral radical intermediates in place of the positively charged activated sites in the biosynthetic pathways.

Science, this issue p. 1078

Oxidative Entry into the Illicium Sesquiterpenes: Enantiospecific Synthesis of (+)-Pseudoanisatin
Co-reporter:Kevin Hung, Matthew L. Condakes, Takahiro Morikawa, and Thomas J. Maimone
Journal of the American Chemical Society 2016 Volume 138(Issue 51) pp:16616-16619
Publication Date(Web):December 14, 2016
DOI:10.1021/jacs.6b11739
Illicium sesquiterpenes have been the subject of numerous synthetic efforts due to their ornate and highly oxidized structures as well as significant biological activities. Herein we report the first chemical synthesis of (+)-pseudoanisatin from the abundant feedstock chemical cedrol (∼$50 USD/kg) in 12 steps using extensive site-selective C(sp3)–H bond functionalization. Significantly, this work represents a novel oxidative strategic template for future approaches to these natural products and their analogs.
Annulative Methods Enable a Total Synthesis of the Complex Meroterpene Berkeleyone A
Co-reporter:Chi P. Ting, Gong Xu, Xianhuang Zeng, and Thomas J. Maimone
Journal of the American Chemical Society 2016 Volume 138(Issue 45) pp:14868-14871
Publication Date(Web):November 3, 2016
DOI:10.1021/jacs.6b10397
Synthetic pathways to complex meroterpenes derived from 3,5-dimethylorsellinic acid (DMOA) and farnesyl pyrophosphate have not been reported despite heavy biosynthetic and medicinal interest. Herein we report the first total synthesis of berkeleyone A, a potential gateway compound to a plethora of fungal-derived meroterpenes, in 13 steps. In addition, we have further developed a novel annulation reaction for the synthesis of hydroxylated 1,3-cyclohexadiones in a single step.
Total Synthesis of Hyperforin
Co-reporter:Chi P. Ting
Journal of the American Chemical Society 2015 Volume 137(Issue 33) pp:10516-10519
Publication Date(Web):August 7, 2015
DOI:10.1021/jacs.5b06939
A 10-step total synthesis of the polycyclic polyprenylated acylphloroglucinol (PPAP) natural product hyperforin from 2-methylcyclopent-2-en-1-one is reported. This route was enabled by a diketene annulation reaction and an oxidative ring expansion strategy designed to complement the presumed biosynthesis of this complex meroterpene. The described work enables the preparation of a highly substituted bicyclo[3.3.1]nonane-1,3,5-trione motif in only six steps and thus serves as a platform for the construction of easily synthesized, highly diverse PPAPs modifiable at every position.
Short, Enantioselective Total Synthesis of Chatancin
Co-reporter:Dr. Yu-Ming Zhao ;Dr. Thomas J. Maimone
Angewandte Chemie International Edition 2015 Volume 54( Issue 4) pp:1223-1226
Publication Date(Web):
DOI:10.1002/anie.201410443

Abstract

An enantioselective total synthesis of the polycyclic diterpene (+)-chatancin, a potent PAF antagonist, is reported. Proceeding in seven steps from dihydrofarnesal, this synthetic route was designed to circumvent macrocyclization-based strategies to complex, cyclized cembranoids. The described synthesis requires only six chromatographic purifications, is high yielding, and avoids protecting-group manipulations. An X-ray crystal structure of this fragile marine natural product was obtained.

Short, Enantioselective Total Synthesis of Chatancin
Co-reporter:Dr. Yu-Ming Zhao ;Dr. Thomas J. Maimone
Angewandte Chemie 2015 Volume 127( Issue 4) pp:1239-1242
Publication Date(Web):
DOI:10.1002/ange.201410443

Abstract

An enantioselective total synthesis of the polycyclic diterpene (+)-chatancin, a potent PAF antagonist, is reported. Proceeding in seven steps from dihydrofarnesal, this synthetic route was designed to circumvent macrocyclization-based strategies to complex, cyclized cembranoids. The described synthesis requires only six chromatographic purifications, is high yielding, and avoids protecting-group manipulations. An X-ray crystal structure of this fragile marine natural product was obtained.

Four-Step Synthesis of the Antimalarial Cardamom Peroxide via an Oxygen Stitching Strategy
Co-reporter:Xirui Hu
Journal of the American Chemical Society 2014 Volume 136(Issue 14) pp:5287-5290
Publication Date(Web):March 20, 2014
DOI:10.1021/ja502208z
A four-step synthesis of the antimalarial terpene cardamom peroxide, a 1,2-dioxepane-containing natural product, is reported from (−)-myrtenal and molecular oxygen. This highly concise route was guided by biosynthetic logic and enabled by an unusual manganese-catalyzed, tandem hydroperoxidation reaction. The absolute configuration of the cardamom peroxide is reported, and its mode of fragmentation following Fe(II)-mediated endoperoxide reduction is established. These studies reveal the generation of reactive intermediates distinct from previously studied endoperoxide natural products.
CH Bond Arylation in the Synthesis of Aryltetralin Lignans: A Short Total Synthesis of Podophyllotoxin
Co-reporter:Chi P. Ting ;Dr. Thomas J. Maimone
Angewandte Chemie International Edition 2014 Volume 53( Issue 12) pp:3115-3119
Publication Date(Web):
DOI:10.1002/anie.201311112

Abstract

A short total synthesis of podophyllotoxin, the prototypical aryltetralin lignan natural product, is reported. Key to the success of this synthetic pathway is a Pd-catalyzed C(sp3)–H arylation reaction enabled by a conformational biasing element to promote C–C reductive elimination over an alternative CN bond-forming pathway. This strategy allows for access to the natural product in five steps from commercially available bromopiperonal, and sheds light on subtle conformational effects governing reductive elimination pathways from high-valent palladium centers.

CH Bond Arylation in the Synthesis of Aryltetralin Lignans: A Short Total Synthesis of Podophyllotoxin
Co-reporter:Chi P. Ting ;Dr. Thomas J. Maimone
Angewandte Chemie 2014 Volume 126( Issue 12) pp:3179-3183
Publication Date(Web):
DOI:10.1002/ange.201311112

Abstract

A short total synthesis of podophyllotoxin, the prototypical aryltetralin lignan natural product, is reported. Key to the success of this synthetic pathway is a Pd-catalyzed C(sp3)–H arylation reaction enabled by a conformational biasing element to promote C–C reductive elimination over an alternative CN bond-forming pathway. This strategy allows for access to the natural product in five steps from commercially available bromopiperonal, and sheds light on subtle conformational effects governing reductive elimination pathways from high-valent palladium centers.

Platensimycin,HPLC>95%
Platensimycin,HPLC>95%
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Platensimycin,HPLC>95%
Cyclopropanemethanol, 2-methyl-2-(4-methyl-3-pentenyl)-, (1S,2S)-
Cyclopropanemethanol, 2-methyl-2-(4-methyl-3-pentenyl)-, (1S,2S)-
CAS:185064-36-2
Cyclopropanemethanol, 2-methyl-2-(4-methyl-3-pentenyl)-, (1S,2S)-
1,3-Dioxolane-4,5-dimethanol,2,2-dimethyl-a,a,a',a'-tetra-2-naphthalenyl-, (4S-trans)- (9CI)
1,3-Dioxolane-4,5-dimethanol,2,2-dimethyl-a,a,a',a'-tetra-2-naphthalenyl-, (4S-trans)- (9CI)
CAS:137365-16-3
1,3-Dioxolane-4,5-dimethanol,2,2-dimethyl-a,a,a',a'-tetra-2-naphthalenyl-, (4S-trans)- (9CI)
Lithium, (5,6-dihydro-1,4-dioxin-2-yl)-
Lithium, (5,6-dihydro-1,4-dioxin-2-yl)-
CAS:83726-22-1
Lithium, (5,6-dihydro-1,4-dioxin-2-yl)-
Cubitene
Cubitene
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Cubitene
Mikanokryptin
Mikanokryptin
CAS:56297-74-6
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1,5a-Propano-5aH-cyclopent[d]oxepin-4,10(5H)-dione,hexahydro-8,8a,11-trihydroxy-1,6,11-trimethyl-, (1R,5aS,6S,8R,8aS,11S)-rel-
1,5a-Propano-5aH-cyclopent[d]oxepin-4,10(5H)-dione,hexahydro-8,8a,11-trihydroxy-1,6,11-trimethyl-, (1R,5aS,6S,8R,8aS,11S)-rel-
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1,5a-Propano-5aH-cyclopent[d]oxepin-4,10(5H)-dione,hexahydro-8,8a,11-trihydroxy-1,6,11-trimethyl-, (1R,5aS,6S,8R,8aS,11S)-rel-
(3aR)-3a,10a-Dihydroxy-5-hydroxymethyl-7c-isopropenyl-2,10t-dimethyl-(3ar,6ac,10at,10bt)-3a,4,6a,7,9,10,10a,10b-octahydro-benz[e]azulen-3,8-dion, Crotophorbolon
(3aR)-3a,10a-Dihydroxy-5-hydroxymethyl-7c-isopropenyl-2,10t-dimethyl-(3ar,6ac,10at,10bt)-3a,4,6a,7,9,10,10a,10b-octahydro-benz[e]azulen-3,8-dion, Crotophorbolon
CAS:18325-99-0
(3aR)-3a,10a-Dihydroxy-5-hydroxymethyl-7c-isopropenyl-2,10t-dimethyl-(3ar,6ac,10at,10bt)-3a,4,6a,7,9,10,10a,10b-octahydro-benz[e]azulen-3,8-dion, Crotophorbolon
Bicyclo[3.3.1]non-3-ene-2,9-dione,4-hydroxy-6-methyl-1,3,7-tris(3-methyl-2-buten-1-yl)-5-(2-methyl-1-oxopropyl)-6-(4-methyl-3-penten-1-yl)-,(1R,5S,6R,7S)-
Bicyclo[3.3.1]non-3-ene-2,9-dione,4-hydroxy-6-methyl-1,3,7-tris(3-methyl-2-buten-1-yl)-5-(2-methyl-1-oxopropyl)-6-(4-methyl-3-penten-1-yl)-,(1R,5S,6R,7S)-
CAS:11079-53-1
Bicyclo[3.3.1]non-3-ene-2,9-dione,4-hydroxy-6-methyl-1,3,7-tris(3-methyl-2-buten-1-yl)-5-(2-methyl-1-oxopropyl)-6-(4-methyl-3-penten-1-yl)-,(1R,5S,6R,7S)-
hapalindole H
hapalindole H
CAS:929706-01-4
hapalindole H