A method of synthesizing a zirconocene dichloride complex, the method comprising contacting a compound of formula ("compound "): wherein R1, R2, and R3 are independently H or (C 1 -C 4)alkyl, or R1 and R3 are bonded together to form a (C 1 -C 4)alkylene and R2 is H or (C 1 -C 4)alkyl, with a compound of formula ("compound "): wherein R4 is H or (C 1 -C 4)alkyl, in the presence of an effective amount of a phosphoric and/or sulfonic acid reagent and under reaction conditions sufficient to make a compound of formula ("compound "): and/or its oxo/R4 regioisomer; wherein R1 to R4 are as defined above. contacting the compound and/or its oxo/R4 regioisomer with either a hydride-functional reducing agent or a (C 1 -C 4)alkyl lithium, under reaction conditions sufficient to make a compound of formula ("compound "): and/or its (HO,R5)/R4 regioisomer, respectively, wherein R1 to R4 are as defined above and R5 is either H or (C 1 -C 4)alkyl, respectively; and contacting the compound and/or its (HO,R5)/R4 regioisomer with dehydration reaction conditions to make a compound of formula ("compound "): and/or its R5/R4 regioisomer, respectively; wherein R1 to R5 are as defined above; contacting the compound and/or its R5/R4 regioisomer with an alkyl lithium under reaction conditions sufficient to make a compound of formula ("compound "): and/or its R5/R4 regioisomer, wherein R1 to R5 are as defined above; and contacting the compound and/or its R5/R4 regioisomer with a compound of formula ("compound "): wherein R6 to R8 independently are H or (C 1 -C 4)alkyl and R9 and R10 independently are H, (C 1 -C 4)alkyl, or R9 and R10 are bonded together and are a (C 3 -C 5)alkylene, under reaction conditions sufficient to make a compound of formula ("compound "): and/or its R5/R4 regioisomer, wherein R1 to R10 are as defined above, wherein the phosphoric and/or sulfonic acid reagent is a mixture of a phosphorous pentoxide and methanesulfonic acid ("P 2 O 5 /H 3 CSO 3 H mixture"), or a reaction product thereof; or a combination of a PPA and a P 2 O 5 /H 3 CSO 3 H mixture, or a reaction product thereof. contacting a compound of formula ("compound "): wherein R1, R2, and R3 are independently H or (C 1 -C 4)alkyl, or R1 and R3 are bonded together to form a (C 1 -C 4)alkylene and R2 is H or (C 1 -C 4)alkyl, with a compound of formula ("compound "): wherein R4 is H or (C 1 -C 4)alkyl, in the presence of an effective amount of a phosphoric and/or sulfonic acid reagent and under reaction conditions sufficient to make a compound of formula ("compound "): and/or its oxo/R4 regioisomer; wherein R1 to R4 are as defined above. contacting the compound and/or its oxo/R4 regioisomer with either a hydride-functional reducing agent or a (C 1 -C 4)alkyl lithium, under reaction conditions sufficient to make a compound of formula ("compound "): and/or its (HO,R5)/R4 regioisomer, respectively, wherein R1 to R4 are as defined above and R5 is either H or (C 1 -C 4)alkyl, respectively; and contacting the compound and/or its (HO,R5)/R4 regioisomer with dehydration reaction conditions to make a compound of formula ("compound "): and/or its R5/R4 regioisomer, respectively; wherein R1 to R5 are as defined above; contacting the compound and/or its R5/R4 regioisomer with an alkyl lithium under reaction conditions sufficient to make a compound of formula ("compound "): and/or its R5/R4 regioisomer, wherein R1 to R5 are as defined above; and contacting the compound and/or its R5/R4 regioisomer with a compound of formula ("compound "): wherein R6 to R8 independently are H or (C 1 -C 4)alkyl and R9 and R10 independently are H, (C 1 -C 4)alkyl, or R9 and R10 are bonded together and are a (C 3 -C 5)alkylene, under reaction conditions sufficient to make a compound of formula ("compound "): and/or its R5/R4 regioisomer, wherein R1 to R10 are as defined above, wherein the phosphoric and/or sulfonic acid reagent is a mixture of a phosphorous pentoxide and methanesulfonic acid ("P 2 O 5 /H 3 CSO 3 H mixture"), or a reaction product thereof; or a combination of a PPA and a P 2 O 5 /H 3 CSO 3 H mixture, or a reaction product thereof.