A one-pot synthesis of (E)-α-bromo-α,β-unsaturated esters and their trifluoromethylation: a general and stereoselective route to (E)-α-trifluoromethyl-α,β-unsaturated esters
摘要:
Bromination of a phosphonate anion derived in situ from ethyl bis (2,2 2 -trifluoroethyl)phosphonoacetate 3 followed by the addition of aldehydes produced (E)-alpha -bromo-alpha,beta -unsaturated esters 5 stereo selectively. The treatment of 5 with FSO2CF2CO2Me and CuI in DMF/HMPA provided (E)-alpha -trifluoromethyl-alpha,beta -unsaturated esters 6. (C) 2001 Elsevier Science Ltd. All rights reserved.
Stereocontrolled Construction of the A-Ring of Nitiol Using a Pauson−Khand Cycloaddition−Ring Fragmentation Strategy
作者:Michael S. Wilson、Gregory R. Dake
DOI:10.1021/ol016002l
日期:2001.6.1
[GRAPHICS]A stereocontrolled construction of the A-ring of nitiol (1) is presented, Key features in this approach are a diastereoselective Pauson-Khand cycloaddition and a Norrish type 1 fragmentation reaction.