Browse
Submit Data
Databases
API
Help

Dataset Information

26 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Enantioselective Total Synthesis of (-)-Deoxoapodine.

ABSTRACT: 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.

SUBMITTER: Kang T

PROVIDER: S-EPMC5647245 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Enantioselective Total Synthesis of (-)-Deoxoapodine.

Kang Taek T White Kolby L KL Mann Tyler J TJ Hoveyda Amir H AH Movassaghi Mohammad M

Angewandte Chemie (International ed. in English) 20170927 44

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-eth ...[more]

PMID: 28862815

Similar Datasets

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 (+)-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-?-carboline and an enantioenriched ?-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 (+)-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 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 (+)-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

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 (+)-Amphirionin-4.

Project description:An enantioselective total synthesis of (+)-amphirionin-4 has been accomplished in a convergent manner. The synthesis features an efficient enzymatic lipase resolution to access the tetrahydrofuranol core in optically active form. The functionalized tetrahydrofuran derivative was synthesized via an oxocarbenium ion-mediated highly diastereoselective syn-allylation reaction. The polyene side chain was synthesized using Stille coupling reactions. Nozaki-Hiyama-Kishi coupling was utilized to construct the C-8 stereocenter and complete the synthesis of (+)-amphirionin-4.

| S-EPMC5328589 | biostudies-literature

Enantioselective total synthesis of bistramide A.

Project description:The enantioselective synthesis of bistramide A has been achieved with a longest linear sequence of 18 steps. The synthetic strategy involves the use of a distereoselective glycolate alkylation, an aldol addition of a chlorotitanium enolate of N-acylthiazolidinthione, and a Sharpless asymmetric epoxidation to synthesize the three key fragments.

| S-EPMC2546575 | biostudies-literature

Enantioselective total synthesis of FD-891.

Project description:The enantioselective synthesis of FD-891 has been achieved with a longest linear sequence of 21 steps. The synthetic strategy involves the use of aldol additions of a chlorotitanium enolate of N-acylthiazolidinethiones as the key reaction to establish 6 of the 10 stereogenic centers. A key cross-metathesis and a late-stage Julia olefination serve to assemble three key subunits.

| S-EPMC2546579 | biostudies-literature

Concise, enantioselective total synthesis of (-)-alstonerine.

Project description:A novel enantioselective total synthesis of (-)-alstonerine has been completed that requires only 15 steps from L-tryptophan. The synthesis features the first application of a Pauson-Khand reaction to synthesize an azabridged bicyclic skeleton. [reaction: see text]

| S-EPMC2516964 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

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