Open Access. Powered by Scholars. Published by Universities.®
Social and Behavioral Sciences Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Social and Behavioral Sciences
Exploiting The Borono-Mannich Reaction In Bioactive Alkaloid Synthesis, Stephen G. Pyne, Christopher Au, Andrew S. Davis, Ian R. Morgan, Thunwadee Ritthiwigrom, Arife Yazici
Exploiting The Borono-Mannich Reaction In Bioactive Alkaloid Synthesis, Stephen G. Pyne, Christopher Au, Andrew S. Davis, Ian R. Morgan, Thunwadee Ritthiwigrom, Arife Yazici
Faculty of Science - Papers (Archive)
We have demonstrated that the borono-Mannich reaction is a versatile and efficient reaction for the diastereoselective preparation of chiral 1,2-amino alcohols. These Mannich products are valuable starting materials as shown in this report by the synthesis of bioactive polyhydroxylated pyrrolizidine and indolizidine alkaloids. Initial studies, directed at the more complex Stemona alkaloids, using the borono-Mannich reaction on cyclic N-acyliminium ions are encouraging as demonstrated by the synthesis of the pyrido[1,2-a]azepine core structure of stemocurtisinol.
Synthesis Of Castanospermine, Theeraphan Machan, Andrew S. Davis, Boonsom Liawruangrath, Stephen G. Pyne
Synthesis Of Castanospermine, Theeraphan Machan, Andrew S. Davis, Boonsom Liawruangrath, Stephen G. Pyne
Faculty of Science - Papers (Archive)
The diastereoselective synthesis of castanospermine is described in 11 synthetic steps from L-xylose. The borono-Mannich reaction between L-xylose, allylamine and (E)-styrene boronic acid gives a tetrahydroxy amine with the desired configurations for C-6, C-7, C-8 and C-8a in the target molecule. A novel pyrrolo[1,2-c]oxazol-3-one precursor was employed to allow for the control of pi-facial diastereoselectivity in an osmium(VIII)-catalysed syn-dihydroxylation (DH) reaction. A regioselective ring-opening of the cyclic sulfate derivative of the resulting diol then secured the C-1 hydroxyl group of castanospermine with the correct configuration. A Mitsunobu cyclization then provided di-O-benzyl castanospermine and …
Diastereoselective Ritter Reactions Of Chiral Cyclic N-Acyliminium Ions: Synthesis Of Pyrido- And Pyrrolo [2,3-D] Oxazoles And 4-Hydroxy-5-N-Acylaminopyrrolidines And 5-Hydroxy-6-N-Acylaminopiperidines, Ian R. Morgan, Arife Yazici, Stephen G. Pyne, Brian W. Skelton
Diastereoselective Ritter Reactions Of Chiral Cyclic N-Acyliminium Ions: Synthesis Of Pyrido- And Pyrrolo [2,3-D] Oxazoles And 4-Hydroxy-5-N-Acylaminopyrrolidines And 5-Hydroxy-6-N-Acylaminopiperidines, Ian R. Morgan, Arife Yazici, Stephen G. Pyne, Brian W. Skelton
Faculty of Science - Papers (Archive)
Pyrido- and pyrrolo[2,3-d]oxazoles can be conveniently prepared in high yield from the Ritter reaction of nitriles and in situ generated chiral cyclic N-acyliminium ions. cis-4-Hydroxy-5-acylaminopyrrolidines and cis-5-hydroxy-6-acylaminopiperidines can be readily obtained by acid hydrolysis of these bicyclic heterocyclic compounds, respectively.