ok so i might not be totally familiar with every specific type of chemical reaction or every single reagent, but the underlying point behind what its saying is very simple witha small amount of scientific knowledge
......if you were more familiar with chemistry's semantics then you'd understand it fine
even if you just rewrite it to, reaction A give chemical A thats then used in reaction B etc. a small amount of research would tell you what each specific reaction or chemical was.
for instance the "benzylic quaternary stererocenter" is simply a molecule, more specifically one that is a ring of 4 carbon subtituents and when changing 2 groups can make a stereoisomer.
so the first sentence says they used cuprate chemistry and sigmatropic rearrangements to make a benzylic quartenary stereocenter....just reaarrange it a bit
maybe i am autistic
but i can understand it myself, and i find it hard to understand why others cant