Diastereoselective schenck ene reaction of singlet oxygen with chiral allylic alcohols; access to enantiomerically enriched 1,2,4-trioxanes
作者:Sunil Sabbani、Louise La Pensée、John Bacsa、Erik Hedenström、Paul M. O'Neill
DOI:10.1016/j.tet.2009.08.020
日期:2009.10
3-methyl-2-butenal catalysed by (+)-MIB or (−)-MIB yielded both the enantiomers of the chiral allylic alcohols 9–11 (90–98% ee), which were subjected to diastereoselectivephotooxygenation in the presence of tetraphenylporphine (TPP) to obtain (R,R)-threo- or (S,S)-threo-β-hydroperoxy alcohols (12–14). Reaction of β-hydroperoxy alcohols (12–14) with different cyclic ketones produced optically active trioxanes