Look at the given synthesis and the provided reagents. Fill in the blanks with the single letter code of the appropriate reagent, or the appropriate descriptive vocabulary word/phrase to complete the description. Remember the computer is very literal so check your spelling carefully. First we add reagent followed by equivalents of reagent followed by workup to give the functional group Then we add reagent followed immediately by reagent and work up to add the needed carbons. Then reagents and will give the (functional group) with stereoselectivity. Lastly reagent will give the final product with stereoselectivity.