After a suitable amount of time, a reducing agent such as NaBH(OAc)3 is added to give the product 17A. Alternatively, when L is a halogen atom such as Cl or Br, and Z is a branched or straight chain alkyl group or ???SO2??? 16A and 8 are combined in a solvent such as DMF in the presence of a tertiary amine base to give the product 17A.