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Stereoselective Additions of Chiral, Functionalized Organozinc Reagents to Achiral and Chiral Aldehydes: a Matched‐Mismatched Case in Organozinc Chemistry
Author(s) -
Koert Ulrich,
Wagner Holger,
Pidun Ulrich
Publication year - 1994
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19941270819
Subject(s) - chemistry , stereoselectivity , reagent , aldehyde , tetrahydrofuran , lewis acids and bases , addition reaction , organic chemistry , denticity , boron trifluoride , diethyl ether , ether , enantioselective synthesis , medicinal chemistry , catalysis , solvent , crystal structure
The additions of the enantiomerically pure organozinc reagents 17 and 33 to the THF‐aldehyde 1 in the presence of the monodentate Lewis acid boron trifluoride—ether give the nonchelation‐controlled addition products 7 and 36 , respectively (stereoselectivity 95:5, 86:14). These results provide a route to oligo(tetrahydrofuran)s with the relative stereochemistry trans ‐ syn ‐ cis. A stereodirecting effect of the chiral center in the organozinc reagent 17 is found, leading to simple diastereoselectivies in the reaction with achiral aldehydes and to a matched‐mismatched case in the reaction with the chiral aldehyde 1 .