![(+)-(1R)-2-acetyl-9-benzyloxycarbonyl-9-azabicyclo[4.2.1]-2-nonene](/Databaselist/images/loading.webp)
64285-06-9Relevant academic research and scientific papers
Efficient new syntheses of (+)and (-)-anatoxin-a. Revised configuration of resolved 9-methyl-9-azabicyclo[4.2.1]nonan-2-one
Ferguson, John R.,Lumbard, Keith W.,Scheinmann, Feodor,Stachulski, Andrew V.,Stjernloef, Peter,Sundell, Staffan
, p. 8867 - 8870 (1995)
The bicyclic ketone 2, as either enantiomer, was converted in high yield to the glycidonitrile 4 by successive base-catalysed condensation with 2-chloropropionitrile and N-dealkylation. Opening of the epoxide followed by elimination of HCl from the resulting α-chloroketone gave the enone 7 which was converted to anatoxin-a 1 by mild acidolysis. Maintenance of chiral homogeneity from both (+)- and (-)2 was demonstrated by diastereomeric amide formation from (+)- and (-)-1. However, the prior correlation of (+)- 2 with (+)- 1 was found to be incorrect; in fact (-)- 2 gives (+)- 1.
A concise asymmetric synthesis of (-)-anatoxin-a using an enantioselective enolisation strategy
Newcombe,Simpkins
, p. 831 - 832 (1995)
The unnatural enantiomer of anatoxin-a is prepared in enantiomerically pure form by a concise route involving enantioselective enolisation of a tropinone derivative by a chiral lithium amide base as the key step.
Investigation of a unified strategy for the synthesis of anatoxin analogues: Scope and limitations
Roe, Stephen J.,Hughes, David L.,Aggarwal, Pooja,Stockman, Robert A.
experimental part, p. 3775 - 3784 (2010/03/30)
Syntheses of the potent neurotoxins and biochemical probes anatoxin-a and homoanatoxin and several analogues by a combined two-directional synthesis-tandem reaction strategy are presented. Key steps include an oxidative desymmetrisation and a tandem Micha
Total synthesis of pinnamine and anatoxin-a via a common intermediate. A caveat on the anatoxin-a endgame
Hjelmgaard, Thomas,Sotofte, Inger,Tanner, David
, p. 5688 - 5697 (2007/10/03)
This paper describes the total synthesis of the naturally occurring alkaloids pinnamine (1) and anatoxin-a (2) from a common enantiomerically pure intermediate (7) easily available from pyroglutamic acid. The synthesis of enantiopure pinnamine proceeded in 10 steps and 4.8% overall yield, and the route was flexible enough to allow stereocontrolled access to a non-natural congener (5-epi-pinnamine) of the natural product. Intramolecular reaction of an N-acyl iminium ion was a key step in the synthesis of both pinnamine and anatoxin-a. However, in stark contrast to literature precedent, complete racemization was observed during the reaction of the N-acyliminium ion leading to the latter alkaloid.
Enantioselective synthesis of (+)-anatoxin-a via enyne metathesis
Brenneman, Jehrod B.,Machauer, Rainer,Martin, Stephen F.
, p. 7301 - 7314 (2007/10/03)
A concise synthesis of the potent nAChR agonist (+)-anatoxin-a (1) has been completed by a series of nine chemical operations and in 27% overall yield from commercially available D-methyl pyroglutamate (12). The strategy featured the application of a new protocol for the diastereoselective synthesis of cis-2,5-disubstituted pyrrolidines bearing unsaturated side chains and an intramolecular enyne metathesis to provide the bridged bicyclic framework of 1. Thus, D-methyl pyroglutamate (12) was converted in five steps to 32, which underwent facile enyne metathesis to deliver the bicyclic diene 33. Selective oxidative cleavage of the less substituted carbon-carbon double bond in 33 followed by deprotection furnished (+)-anatoxin-a (1).
Synthesis of (±)-anatoxin-α and analogues
Parsons, Philip J.,Camp, Nicholas P.,Edwards, Neil,Ravi Sumoreeah
, p. 309 - 315 (2007/10/03)
A new and highly efficient synthesis of the potent nicotinic acetylcholine receptor agonist, anatoxin-α and its analogues is described, which uses a β-lactam ring opening-transannular cyclisation sequence to set up the bridged bicyclic framework of the natural product. The synthesis involves a cycloaddition of chlorosulfonyl isocyanate with cyclooctadiene followed by Boc protection of the resulting β-lactam. Reaction of the β- lactam with a variety of nucleophiles, followed by selenium-mediated cyclisation and oxidation gave the skeleton of anatoxin-α bearing various sidechains. The approach offers a flexible entry to useful quantities of anatoxin-α and its analogues.
Tandem reactions of anions: A short and efficient route to ±anatoxin-a
Parsons, Philip J.,Camp, Nicholas P.,Underwood, J. Mark,Harvey, Darren M.
, p. 11637 - 11642 (2007/10/03)
A new route to anatoxin-a (1) is reported which involves an anionically induced small ring opening/ring closure/ring opening cascade. The azabicyclo [4.2.1]nonane ring system of anatoxin-α is hence formed in one synthetic operation.
A short and enantioselective synthesis of (+)-Anatoxin-a
Somfai,Ahman
, p. 3791 - 3794 (2007/10/02)
A short and enantioselective total synthesis of the neurotoxic alkaloid (+)-Anatoxin-a (1) from the L-pyroglutamic acid derivative 2 is described. The key step involves an intramolecular cyclisation of an N-tosyl iminium ion derived from the corresponding α-methoxy sulfonamide.
A New Method of Formation of 9-Azabicyclononane Skeleton and Its Application to Synthesis of (+/-)-Anatoxin a
Shono, Tatsuya,Matsumura, Yoshihiro,Uchida, Kenshi,Tagami, Katsumi
, p. 919 - 922 (2007/10/02)
9-Azabicyclo-nonane skeleton was formed in one step by Lewis acid promoted reaction between 1-methoxycarbonyl-2,5-dimethoxypyrrolidine and 1-ethoxy-1-trimethylsiloxy-1,4-pentadiene, and it was converted to (+/-)-anatoxin a.
