e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
Rational synthesis of contra-thermodynamic spiroacetals by reductive cyclizations
LR Takaoka, AJ Buckmelter, TE LaCruz…
Index: Takaoka, Leo R.; Buckmelter, Alexandre J.; LaCruz, Thomas E.; Rychnovsky, Scott D. Journal of the American Chemical Society, 2005 , vol. 127, # 2 p. 528 - 529
A synthesis of spiroacetals was developed using a reductive cyclization strategy that leads stereoselectively to spiroacetals with a single anomeric stabilization. The method begins with the synthesis of spiro ortho esters. The ortho ester is converted to a cyano acetal. Reductive lithiation of the cyano acetal generates an axial dialkoxylithium reagent, and intramolecular cyclization produces a new ring with retention of configuration. The strategy ...
