The invention relates to an asymmetric synthesis method of (R,R)-
formoterol tartrate, which comprises the following steps: by taking (S,S)-CsDPEN and
transition metal complex as a catalyst, performing asymmetric
hydrogen transfer reaction on alpha-bromoketone used as a
raw material, thus obtaining a chiral
alcohol intermediate compound; performing reaction steps of nitro-reduction,
formylation, cyclization and the like, thus obtaining a key intermediate compound FM 1; by taking Pt / C as a catalyst and alpha-methylphenylethylamine as a chiral assistant, synthesizing an intermediate compound FM 2-3; performing
tartaric acid salification,
ionization and alpha-methylphenethyl removal, and reacting with
benzaldehyde, thus preparing a
chiral amine intermediate compound FM 2; reacting and
coupling the two key intermediate compounds, and performing protective group removal to obtain (R,R)-
formoterol FM 4; and performing
tartaric acid salification on the FM 4, thus preparing the target product (R,R)-
formoterol tartrate FM 5. According to the invention, the (R,R)-formoterol is synthesized through an asymmetric
hydrogen transfer method by means of the chiral assistant, and high yield and favorable ee value are achieved. Compared with a chemical resolution method for synthesizing chiral formoterol, the method provided by the invention has the advantages of high overall yield, mild
reaction conditions, low cost and the like, thereby being beneficial to industrial production.