Silylative Dieckmann-like cyclizations of ester-imides (and diesters).
[Structure: see text] Trialkylsilyl triflates effect cyclization of ester-imides such as 2 to produce adducts such as 4a. Trapping of the in situ generated, nucleophilic ketene acetal (cf. 5a) is a key aspect of the transformation. A range of substrates amenable to this operationally simple reaction is reported. In many instances the levels of diastereoselectivity are very high. Mechanistic points are inferred from spectroscopic observations.
Hoye
Thomas R
TR
Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA. hoye@chem.umn.edu
Dvornikovs
Vadims
V
Sizova
Elena
E
D003500:Cyclization; D004952:Esters / Q000737:chemistry*; D007094:Imides / Q000737:chemistry*; D015394:Molecular Structure; D011763:Pyrrolizidine Alkaloids / Q000737:chemistry
D004952:Esters; D007094:Imides; D011763:Pyrrolizidine Alkaloids; C409195:UCS 1025A