This reaction requires an inert solvent such as dichloromethane or toluene or tetrahydrofuran and activation by one or more of: (1) an acid catalyst, such as TFA; (2) a desilylating agent such as silver fluoride; (3) heating.The compound of general formula (XIII) obtained from the cycloaddition reaction is a racemate and may require resolution into its constituent enantiomers, which can be achieve