Patent ID: 8258323

Claim:
A process for preparing d-NBV of formula which comprises: a) reacting 2,2-dimethyl-1,3 dioxolane-4-carbaldehyde of formula with a vinyl Grignard reagent, to obtain a compound of formula IIa in the form of diastereoisomeric mixture (S,R+R,R) w) reacting the above compound of formula IIa with 2-bromo-4-fluorophenol or 2-bromo-4-fluorophenyl acetate by means of a palladium catalysed C—C coupling reaction, to obtain a compound of formula XIa in the form of diastereoisomeric mixture (S,R+R,R) x) reducing the above compound of formula XIa to obtain a compound of formula Va in the form of diastereoisomeric mixture (S,R+R,R) and, if desired, separating the compound of formula Va (S,R+R,R) into the single diastereomer Va (S,R) and the single diastereomer Va (R,R).