96248-94-1

Upstream product

• 125109-97-9 (1S,5S)-N-methoxycarbonyl-1,2,3,4,5,6-hexahydro-1,5-methanopyrido-[1,2-a][1,5]diazocin-8-one 
• 23581-42-2 octahydro-2H-quinolizine-2-one 
• 2739-99-3 2-ethoxycarbonylmethylpiperidine 
• 2739-98-2 ethyl 2-(pyridinyl-2)acetate 
• 99392-94-6 1-(2-ethoxycarbonyl)ethyl-2-ethoxycarbonylmethylpiperidine 
• 98202-45-0 ethyl (2E)-7-iodohept-2-enoate 
• 1258431-03-6 2-oxo-octahydro-quinolizine-3-carboxylic acid ethyl ester 
• 15191-27-2 1,2,3,4,5,6-hexahydro-1,5-methano-pyrido[1,2-a][1,5]diazocin-8-one 

Relevant academic research and scientific papers

Stereocontrolled synthesis and alkylation of cyclic β-amino esters: Asymmetric synthesis of a (-)-sparteine surrogate

A convenient method for the stereoselective synthesis of cyclic β-amino esters from an iodo αβ-unsaturated ester and α-methylbenzylamine is described. Subsequent enolate generation and alkylation proceeds with complete stereocontrol, with the two stereogenic centres working together. In this way, a functionalised piperidine suitable for alkaloid natural product synthesis was prepared. The usefulness of the methodology is exemplified with the concise synthesis of a (-)-sparteine surrogate. The Royal Society of Chemistry.

Synthesis of sparteine-like chiral diamines and evaluation in the enantioselective lithiation-substitution of N-(tert-butoxycarbonyl)-pyrrolidine

Three chiral diamines were synthesised and evaluated as sparteine surrogates in the lithiation-substitution of N-(tert-butoxycarbonyl)pyrrolidine. The synthesis and attempted resolution of sparteine-like diamines {(1S*, 2R*, 8R*)-10-methyl-6,10-diazatricyclo [6.3.1.02,6]dodecane and (1S*, 2R*, 9R*)-11-methyl-7,11-diazatricyclo[7.3.1.02,7]tridecane} (via inclusion complex formation) are reported. Unfortunately, it was only possible to resolve the diazatricyclo-[7.3.1.02,7] tridecane compound. An alternative route to (1R,2S,9S)-11-methyl-7,11-diazatricyclo[7.3.1.02.7]tridecane starting from the natural product, (-)-cytisine, is described. This simple three-step route furnished gram-quantities of a (+)-sparteine surrogate. X-ray crystallography of an intermediate in the route, (1R,5S,12S)-3-methoxycarbonyl-decahydro-1,5-methanopyrido [1,2-a][1,5]diazocin-8-one, enabled the stereochemistry of all of the tricyclic diamines described in this paper to be unequivocally established. Two other diamines, starting from (S)-proline and resolved 2-piperidine ethanol, were prepared using standard methods. These diamines lacked the bispidine framework of (-)-sparteine and were found to impart vastly inferior enantioselectivity. It was concluded that, for the asymmetric lithiation-substitution of N-Boc pyrrolidine, a rigid bispidine framework and only three of the four rings of (-)-sparteine are needed for high enantioselectivity. Furthermore, it is shown that diamine (1R,2S,9S)-11-methyl-7,11-diazatricyclo [7.3.1.02,7]tridecane is the first successful (+)-sparteine surrogate.

A readily-accessible (+)-sparteine surrogate

A "(+)-sparteine-like" chiral diamine, readily synthesized in three steps from (-)-cytisine, has been evaluated in four different asymmetric transformations; in each case, selectivity in an enantiocomplementary fashion to (-)-sparteine was observed. Copyright