The Stereoselective Introduction of the C15 OH Group on the W

Multiple Choice

The stereoselective introduction of the C15 OH group on the w side chain of prostaglandins has presented a challenge for synthetic chemists.Recently,Mulzer and co-workers demonstrated a new route in which the w side chain is synthesized independently and then attached to the bicyclic counterpart.What is the appropriate sequence of reagents for the following synthesis?

A) (1) PBr₃; (2) Grubbs' catalyst,Reagent X; (3) KOC(CH₃) ₃
B) (1) PCC; (2) Ph₃P=CH₂; (3) Grubbs' catalyst,Reagent X
C) (1) PBr₃; (2) Ph₃P=CH₂; (3) Grubbs' catalyst,Reagent X
D) (1) TsCl,pyridine; (2) Grubbs' catalyst,Reagent X; (3) KOC(CH₃) ₃