161109-64-4Relevant academic research and scientific papers
Functionalised 2,3-dimethyl-3-aminotetrahydrofuran-4-one and N-(3-oxo-hexahydrocyclopenta[b]furan-3a-yl)acylamide based scaffolds: Synthesis and cysteinyl proteinase inhibition
Watts, John,Benn, Alex,Flinn, Nick,Monk, Tracy,Ramjee, Manoj,Ray, Peter,Wang, Yikang,Quibell, Martin
, p. 2903 - 2925 (2007/10/03)
A stereoselective synthesis of functionalised (2R,3R)-2,3-dimethyl-3- amidotetrahydrofuran-4-one, its (2S,3R)-epimer and (3aR,6aR)-N-(3-oxo- hexahydrocyclopenta[b]furan-3a-yl)acylamide cysteinyl proteinase inhibitors has been developed using Fmoc-protected scaffolds 6-8 in a solid-phase combinatorial strategy. Within these scaffolds, the introduction of an alkyl substituent α to the ketone affords chiral stability to an otherwise configurationally labile molecule. Preparation of scaffolds 6-8 required stereoselective syntheses of suitably protected α-diazomethylketone intermediates 9-11, derived from appropriately protected α-methylthreonines (2R,3R)-12, (2R,3S)-13 and a protected analogue of (1R,2R)-1-amino-2- hydroxycyclopentanecarboxylic acid 14. Application of standard methods for the preparation of amino acid α-diazomethylketones, through treatment of the mixed anhydride or pre-formed acyl fluorides of intermediates 12-14 with diazomethane, proved troublesome giving complex mixtures. However, the desired α-diazomethylketones were isolated and following a lithium chloride/acetic acid promoted insertion reaction provided scaffolds 6-8. Elaboration of 6-8 on the solid phase gave α,β-dimethyl monocyclic ketone based inhibitors 38a-f, 39a,b,d,e,f and bicyclic inhibitors 40a-e that exhibited low micromolar activity against a variety of cysteinyl proteinases.
