88002-11-3Relevant academic research and scientific papers
Chiral Induction in Photochemical Reactions, II - Regio- and Diastereoselectivity in the Oxetane Formation of Chiral Phenylglyoxylates with Electron Rich Olefins
Koch, Hartmut,Scharf, Hans-Dieter,Runsink, Jan,Leismann, Hans
, p. 1485 - 1503 (2007/10/02)
In the photochemical oxetane formation of chiral phenylglyoxylates with 3 high diastereoselectivities and lower regioselectivities are achieved with 1a and 1d.The lower regio- and diastereoselectivities observed with 1c, 1e, and 1g can be rationalized by the influence of the chiral alcohol on the conformation of the keto ester and on the different steric hindrances of the cis (face-position) or trans (edge-position) diradicals 5 or 7.In agreement with this model the differences of activation parameters obtained for the regio- and diastereoselectivities of 5b and 7b are discussed.By variation of the starting olefins we observed an increase of the diastereoselectivity of oxetane formation in the sequence 8 ca. 7 5 4, caused by increasing control of the cis-diradical (face-position).
