Synthesis of diamino-furostan sapogenins and their use as scaffolds for positioning peptides in a preorganized form

A Multiple Multicomponent Approach to Chimeric Peptide–Peptoid Podands

“…[25] Whereas procedures toward axial aminosteroids are well-established, [26,27] the functionalization of steroids with various axial isocyano groups has not been reported so far. [25] Whereas procedures toward axial aminosteroids are well-established, [26,27] the functionalization of steroids with various axial isocyano groups has not been reported so far.…”

“…[22,25,29] Compared with the general methodology used to produce peptido-steroidal receptors through traditional peptide-couplings, the present approach shows greater promise in terms of speed, versatility, atom economy, and binding-motif-generation, especially if sequential approaches are implemented for growing oligochimeric peptide-peptoid chains. Chimeric peptido-cho-A C H T U N G T R E N N U N G lanes derived from N a -Boc-protected l-tryptophan, l-histidine, and L-phenylalanine on cholane polyisonitriles 27, 29, and 31, respectively, formed readily, thereby offering a very diverse array of chimeric peptide-peptoid chains attached to a cis A/B-steroidal skeleton.…”

“…Scheme 4 shows the synthesis of spirostanic and furostanic diisonitriles from the corresponding amino derivatives. [25] Whereas procedures toward axial aminosteroids are well-established, [26,27] the functionalization of steroids with various axial isocyano groups has not been reported so far. Our approach started with the double formylation of the 3a,7a-di-A C H T U N G T R E N N U N G amino-spirostane 17, previously prepared from the natural sapogenin diosgenin according to a reported procedure.…”

“…Our approach started with the double formylation of the 3a,7a-di-A C H T U N G T R E N N U N G amino-spirostane 17, previously prepared from the natural sapogenin diosgenin according to a reported procedure. [25] From the different formylation protocols reported for aliphatic amines, the use of ethyl or methyl formate heated at reflux proved ineffective due to the low reactivity of both axial amines, but the mixed formic-acetic anhydride method afforded diformamide 18 in quantitative yield. This compound was submitted to dehydration using the traditional POCl 3 /Et 3 N procedure to furnish 3a,7a-diisocyano-spirostane 19 in 81 % yield, thus proving the efficiency of this simple method also on steroids.…”

Combinatorial Chemistry Online

“…This work constitutes the first report on the use of furostanic sapogenins as scaffolds for positioning natural amino acids and (cyclo)peptides. 10 The broad and potent activity of 4-thiazolidinones has established it as one of the biologically important scaffolds.…”