Browse
Submit Data
Databases
API
Help

Dataset Information

17 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Enantioselective total synthesis of (+)-lithospermic acid.

ABSTRACT: An enantioselective synthesis of (+)-lithospermic acid, a potent anti-HIV agent, has been accomplished in a convergent manner in nine steps. The synthesis features an enantioselective intramolecular oxa-Michael addition catalyzed by a quinidine derivative, a hypervalent iodine-mediated rearrangement of chromanone to dihydrobenzofuran, an enantioselective ?-oxyamination, and an intermolecular C-H olefination.

SUBMITTER: Ghosh AK

PROVIDER: S-EPMC3482163 | biostudies-literature | 2012 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Enantioselective total synthesis of (+)-lithospermic acid.

Ghosh Arun K AK Cheng Xu X Zhou Bing B

Organic letters 20120914 19

An enantioselective synthesis of (+)-lithospermic acid, a potent anti-HIV agent, has been accomplished in a convergent manner in nine steps. The synthesis features an enantioselective intramolecular oxa-Michael addition catalyzed by a quinidine derivative, a hypervalent iodine-mediated rearrangement of chromanone to dihydrobenzofuran, an enantioselective α-oxyamination, and an intermolecular C-H olefination. ...[more]

PMID: 22978790

Similar Datasets

Enantioselective total synthesis of plectosphaeroic acid B.

Project description:The first total synthesis of a member of the plectosphaeroic acid family of fungal natural products is reported. Key steps include the late-stage formation of the hindered N6-C9" bond and stereoselective introduction of the two methylthio substituents.

| S-EPMC3611964 | biostudies-literature

Catalytic enantioselective total synthesis of (+)-eucomic acid.

Project description:A catalytic enantioselective synthesis of (+)-eucomic acid is reported. A palladium-catalyzed asymmetric allylic alkylation is employed to access the chiral tetrasubstituted α-hydroxyacid moiety found in the natural product. The protecting group strategy was investigated, and a protecting group manipulation was made without any appreciable deleterious effects in the allylic alkylation reaction. Non-natural (+)-eucomic acid is synthesized in a longest linear sequence of 13 steps.

| S-EPMC4986999 | biostudies-literature

Highly convergent total synthesis of (+)-lithospermic acid via a late-stage intermolecular C-H olefination.

Project description:The total synthesis of (+)-lithospermic acid is reported, which exploits two successive C-H activation reactions as key steps. Rh-catalyzed carbene C-H insertion reaction utilizing Davies's catalyst was used to forge dihydrobenzofuran core, and a late-stage intermolecular C-H olefination coupled the olefin unit with the dihydrobenzofuran core to construct the molecule in a highly convergent manner.

| S-EPMC3085405 | biostudies-literature

Enantioselective total synthesis of aplyviolene.

Project description:The enantioselective total synthesis of the rearranged spongian diterpene aplyviolene has been completed in 14 steps from the known hydroazulenone 8. The key junction of the hydrocarbon and oxygenated fragments to form the critical C8 quaternary carbon stereocenter and set the stage for elaborating the delicate bicyclic lactone functionality was accomplished in high yield and exquisite stereoselectivity by Michael addition of an enantioenriched hydroazulenone enolate to an enantiopure ?-bromocyclopentenone.

| S-EPMC3205941 | biostudies-other

Enantioselective total synthesis of (-)-acutumine.

Project description:An account of the total synthesis of the tetracyclic alkaloid (-)-acutumine is presented. A first-generation approach to the spirocyclic subunit was unsuccessful as a result of incorrect regioselectivity in a radical cyclization. However, this work spawned a second-generation strategy in which the spirocycle was fashioned via a radical-polar crossover reaction. This process merged an intramolecular radical conjugate addition with an enolate hydroxylation and created two stereocenters with excellent diastereoselectivity. The reaction was promoted by irradiation with a sunlamp, and a ditin reagent was required for aryl radical formation. These facts suggest that the substrate may function as a sensitizer, thereby facilitating homolytic cleavage of the ditin reagent. The propellane motif of the target was then installed via annulation of a pyrrolidine ring onto the spirocycle. The sequence of reactions used included a phenolic oxidation, an asymmetric ketone allylation mediated by Nakamura's chiral allylzinc reagent, an anionic oxy-Cope rearrangement, a one-pot ozonolysis-reductive amination, and a Lewis acid promoted cyclization of an amine onto an alpha,beta-unsaturated dimethyl ketal. Further studies of the asymmetric ketone allylation demonstrated the ability of the Nakamura reagent to function well in a mismatched situation. A TiCl(4)-catalyzed regioselective methyl enol etherification of a 1,3-diketone completed the synthesis.

| S-EPMC2790369 | biostudies-literature

Enantioselective total synthesis of (+)-amabiline.

Project description:The first total synthesis of (+)-amabiline, an unsaturated pyrrolizidine alkaloid from Cynoglossum amabile, is reported. This convergent, enantioselective synthesis proceeds in 15 steps (10-step longest linear sequence) in 6.2% overall yield and features novel methodology to construct the unsaturated pyrrolizidine or (-)-supinidine core.

| S-EPMC3359844 | biostudies-literature

Enantioselective Total Synthesis of (-)-Deoxoapodine.

Project description:The first enantioselective total synthesis of (-)-deoxoapodine is described. Our synthesis of this hexacyclic aspidosperma alkaloid includes an efficient molybdenum-catalyzed enantioselective ring-closing metathesis reaction for the desymmetrization of an advanced intermediate that introduces the C5-quaternary stereocenter. After C21-oxygenation, the pentacyclic core was accessed by electrophilic C19-amide activation and transannular spirocyclization. A biogenetically inspired dehydrative C6-etherification reaction proved highly effective to secure the F-ring and the fourth contiguous stereocenter of (-)-deoxoapodine with complete stereochemical control.

| S-EPMC5647245 | biostudies-literature

Enantioselective total synthesis of lycopodine.

Project description:The first enantioselective total synthesis of lycopodine has been completed. Key steps include a highly diastereoselective organocatalyzed cyclization of a keto sulfone to establish the key C7 and C8 stereocenters and a tandem 1,3-sulfonyl shift/intramolecular Mannich cyclization to form the tricyclic core.

| S-EPMC2528287 | biostudies-literature

Enantioselective total synthesis of (+)-reserpine.

Project description:A catalytic, enantioselective synthesis of (+)-reserpine is reported. The route features a highly diastereoselective, chiral catalyst-controlled formal aza-Diels-Alder reaction between a 6-methoxytryptamine-derived dihydro-β-carboline and an enantioenriched α-substituted enone to form a key tetracyclic intermediate. This approach addresses the challenge of setting the C3 stereogenic center by using catalyst control. Elaboration of the tetracycle to (+)-reserpine includes an intramolecular aldol cyclization and a highly diastereoselective hydrogenation of a sterically hindered enoate.

| S-EPMC3578295 | biostudies-literature

Enantioselective Total Synthesis of (+)-Heilonine.

Project description:Chemical transformations that rapidly and efficiently construct a high level of molecular complexity in a single step are perhaps the most valuable in total synthesis. Among such transformations is the transition metal catalyzed [2 + 2 + 2] cycloisomerization reaction, which forges three new C-C bonds and one or more rings in a single synthetic operation. We report here a strategy that leverages this transformation to open de novo access to the Veratrum family of alkaloids. The highly convergent approach described herein includes (i) the enantioselective synthesis of a diyne fragment containing the steroidal A/B rings, (ii) the asymmetric synthesis of a propargyl-substituted piperidinone (F ring) unit, (iii) the high-yielding union of the above fragments, and (iv) the intramolecular [2 + 2 + 2] cycloisomerization reaction of the resulting carbon framework to construct in a single step the remaining three rings (C/D/E) of the hexacyclic cevanine skeleton. Efficient late-stage maneuvers culminated in the first total synthesis of heilonine (1), achieved in 21 steps starting from ethyl vinyl ketone.

| S-EPMC8517970 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data