Chiral Vinyl Anions for "Carbonyl Umpolung". Non-Chelate-Controlled Addition of an Enantiomerically Pure Vinyllithium Reagent toO-Protected 3-Hydroxybutyraldehydes

All articles of this category ( 2R , 4R )-2,4-Dibenzyloxy-1-pentanol ( 7 ) is available by stereoselective reaction of the chiral vinyllithium reagent 1b (( R )-1-bromo-1-lithio-3-[(2-methoxyethoxy)methoxy]-1-butene) with ( R )-3-benzyloxybutyraldehyde ( 2 ). Thus, the addition of a methanol-d 1 -synthon ( - CH 2 OH) to O -protected 3-hydroxybutyraldehydes is possible in a "non-chelate-controlled" manner.