Intramolecular Chromium(II)-Catalyzed Pinacol Cross Coupling of 2-Methylene-α,ω-dicarbonyls
作者:Ulrich Groth、Marc Jung、Till Vogel
DOI:10.1055/s-2004-822895
日期:——
Using only 10% of CrCl2 as catalyst, manganese-powder as reducing agent and TMSCl as scavenger, 2-methylene-α,Ï-dialdehydes and -ketones can be coupled to form cyclic diols diastereoselectively. The diastereomeric excess strongly depends on the ring size and the substituents of the Ï-carbonyl group. The greater the ring size the higher diastereoselectivities are observed. In all cases cis-diols are preferentially formed.