The one step transformation of esters into secondary alcohols (70-80% yield
s) has been performed with a Grignard reagent in the presence of calcium or
zinc borohydride. Under the same conditions, vinylic Grignard reagents gav
e gamma,delta-unsaturated alcohols in good yields through three successive
reactions : addition to the eater carbonyl, then conjugate addition and, fi
nally reduction).