Hendrickson's Reagent

Dehydration reagent in organic synthesis.

Hendrickson's Reagent can be used to derivatize chiral monoesters via stereoselective aldol addition; forming O-silyl orthoesters and cyclic phosphonates.

(R)-1,1,2-triphenylethane-1,2-diol [(R)-(1)] is easily available from commercial (R)-Mandelic Acid, which is  first esterified to give methyl mandelate and then treated with Phenylmagnesium Bromide (3.5 equiv). In an analogous way, (S)-(1)  is accessible from (S)-mandelic acid, which is also commercially available (eq 1).