An Efficient Synthetic Approach to Polycyclic 2,5-Dihydropyrroles from α-Silyloxy Ketones
摘要:
A three-step sequence to prepare polycyclic 2,5-dihydropyrroles from alpha-silyloxy ketones is presented. A Lewis acid-mediated ring fragmentation of cyclic gamma-sjlyloxy-beta-hydroxy-alpha-diazo esters provided tethered aldehyde ynoate intermediates which, when treated with amino acid silyl esters, underwent intramolecular azomethine ylide 1,3-dipolar cycloadditions. The 2,5-dihydropyrrole products were formed in good to excellent yield as single diastereomers.
Sustainable and efficient manufacturing methods for N-methylated peptides remain underexplored despite growing interest in therapeutic N-methylated peptides within the pharmaceutical industry. A methodology for the coupling of C-terminally unprotected N-methylamino acids mediated by an isostearic acid halide (ISTAX) and silylating reagent has been developed. This approach allows for the coupling of
作者:Nitinkumar D. Jabre、Teruki Watanabe、Matthias Brewer
DOI:10.1016/j.tetlet.2013.10.152
日期:2014.1
A ring fragmentation and intramolecular azomethine ylide 1,3-dipolar cycloaddition sequence of reactions was successfully used in the preparation of a known (+/-)-cycloclavine precursor in good overall yield. Results of efforts to incorporate the tetrasubstituted cyclopropane ring present in cycloclavine are also discussed. (C) 2013 Elsevier Ltd. All rights reserved.
The stabilized iminium ylide-olefin [3+2] cyloaddition reaction. Total synthesis of Sceletium alkaloid A4
作者:Pat N. Confalone、Edward M. Huie
DOI:10.1021/ja00335a051
日期:1984.11
Ruehlmann,K. et al., Journal fur praktische Chemie (Leipzig 1954), 1966, vol. 32, p. 37 - 42
作者:Ruehlmann,K. et al.
DOI:——
日期:——
An Efficient Synthetic Approach to Polycyclic 2,5-Dihydropyrroles from α-Silyloxy Ketones
A three-step sequence to prepare polycyclic 2,5-dihydropyrroles from alpha-silyloxy ketones is presented. A Lewis acid-mediated ring fragmentation of cyclic gamma-sjlyloxy-beta-hydroxy-alpha-diazo esters provided tethered aldehyde ynoate intermediates which, when treated with amino acid silyl esters, underwent intramolecular azomethine ylide 1,3-dipolar cycloadditions. The 2,5-dihydropyrrole products were formed in good to excellent yield as single diastereomers.