Reaction of 1-silyloxybicyclo[n.1.0]alkanes with iron(III) chlorides. A facile synthesis of 2-cycloalkenones via ring enlargement of cyclic ketones

1976 ◽  
Vol 41 (11) ◽  
pp. 2073-2074 ◽  
Author(s):  
Yoshihiko. Ito ◽  
Syotaro. Fujii ◽  
Takeo. Saegusa
Keyword(s):  
Cyclic Ketones ◽  
Facile Synthesis ◽  
Ring Enlargement

scholarly journals Facile synthesis of 1-alkoxy-1H-benzo- and 7-azabenzotriazoles from peptide coupling agents, mechanistic studies, and synthetic applications

2014 ◽  
Vol 10 ◽  
pp. 1919-1932 ◽  
Author(s):  
Mahesh K Lakshman ◽  
Manish K Singh ◽  
Mukesh Kumar ◽  
Raghu Ram Chamala ◽  
Vijayender R Yedulla ◽  
...  
Keyword(s):  
Amide Bond ◽  
Coupling Agents ◽  
Cyclic Ketones ◽  
Substitution Reactions ◽  
Facile Synthesis ◽  
Reaction Conditions ◽  
Peptide Coupling ◽  
Acyclic Nucleoside ◽  
Derivatives Of

(1H-Benzo[d][1,2,3]triazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP), 1H-benzo[d][1,2,3]triazol-1-yl 4-methylbenzenesulfonate (Bt-OTs), and 3H-[1,2,3]triazolo[4,5-b]pyridine-3-yl 4-methylbenzenesulfonate (At-OTs) are classically utilized in peptide synthesis for amide-bond formation. However, a previously undescribed reaction of these compounds with alcohols in the presence of a base, leads to 1-alkoxy-1H-benzo- (Bt-OR) and 7-azabenzotriazoles (At-OR). Although BOP undergoes reactions with alcohols to furnish 1-alkoxy-1H-benzotriazoles, Bt-OTs proved to be superior. Both, primary and secondary alcohols undergo reaction under generally mild reaction conditions. Correspondingly, 1-alkoxy-1H-7-azabenzotriazoles were synthesized from At-OTs. Mechanistically, there are three pathways by which these peptide-coupling agents can react with alcohols. From 31P{1H}, [18O]-labeling, and other chemical experiments, phosphonium and tosylate derivatives of alcohols seem to be intermediates. These then react with BtO− and AtO− produced in situ. In order to demonstrate broader utility, this novel reaction has been used to prepare a series of acyclic nucleoside-like compounds. Because BtO− is a nucleofuge, several Bt-OCH2Ar substrates have been evaluated in nucleophilic substitution reactions. Finally, the possible formation of Pd π–allyl complexes by departure of BtO− has been queried. Thus, alpha-allylation of three cyclic ketones was evaluated with 1-(cinnamyloxy)-1H-benzo[d][1,2,3]triazole, via in situ formation of pyrrolidine enamines and Pd catalysis.

A Direct Retro-Reformatsky Fragmentation:  Formal Ring Enlargement of Cyclic Ketones for Novel and Practical Synthesis of Heterocyclic Enamines

2004 ◽  
Vol 69 (3) ◽  
pp. 997-1000 ◽  
Author(s):  
Mei-Xin Zhao ◽  
Mei-Xiang Wang ◽  
Chu-Yi Yu ◽  
Zhi-Tang Huang ◽  
George W. J. Fleet
Keyword(s):  
Cyclic Ketones ◽  
Ring Enlargement ◽  
Practical Synthesis ◽  
Heterocyclic Enamines

The Preparation of Cyclic Ketones by Ring Enlargement

1939 ◽  
Vol 61 (5) ◽  
pp. 1057-1061 ◽  
Author(s):  
E. P. Kohler ◽  
M. Tishler ◽  
H. Potter ◽  
H. T. Thompson
Keyword(s):  
Cyclic Ketones ◽  
Ring Enlargement

New method for the ring enlargement of cyclic ketones

1982 ◽  
Vol 23 (9) ◽  
pp. 983-986 ◽  
Author(s):  
D. Labar ◽  
J.L. Laboureur ◽  
A. Krief
Keyword(s):  
New Method ◽  
Cyclic Ketones ◽  
Ring Enlargement

scholarly journals A Direct Retro-Reformatsky Fragmentation: Formal Ring Enlargement of Cyclic Ketones for Novel and Practical Synthesis of Heterocyclic Enamines.

ChemInform ◽  
2004 ◽  
Vol 35 (26) ◽  
Author(s):  
Mei-Xin Zhao ◽  
Mei-Xiang Wang ◽  
Chu-Yi Yu ◽  
Zhi-Tang Huang ◽  
George W. J. Fleet
Keyword(s):  
Cyclic Ketones ◽  
Ring Enlargement ◽  
Practical Synthesis ◽  
Heterocyclic Enamines

Original method for the ring enlargement of cyclic ketones

1984 ◽  
Vol 25 (25) ◽  
pp. 2713-2716 ◽  
Author(s):  
J.L. Laboureur ◽  
A. Krief
Keyword(s):  
Original Method ◽  
Cyclic Ketones ◽  
Ring Enlargement
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