"Propose a synthesis of ( )-Juvabione from cyclohexane-1,4-dione and acetylene. Your synthesis must include at least one pericyclic reaction and one organometallic coupling step."
Key concepts
Cyclohexene, chiral auxiliaries (e.g., Evans oxazolidinone), and any inorganic reagents. advanced organic chemistry practice problems
Reactions look different on different molecules, but the underlying electronics are the same. Learn to see the core functional group patterns beneath complex molecular structures.
Solution
To sharpen your skills, try to solve the following problems before reviewing the explanations. Problem A: Pericyclic Reaction Stereochemistry
Account for the stability of the intermediate allylic radicals. Learn to see the core functional group patterns
) removes an adjacent proton. This forms a stable, highly substituted alkene inside the five-membered ring. 3. Molecular Spectroscopy and Structure Elucidation
Pericyclic reactions occur via concerted pathways through cyclic transition states. They are governed strictly by the conservation of orbital symmetry (Woodward-Hoffmann rules). Key Classes of Pericyclic Reactions ) removes an adjacent proton
The attack yields the diastereomer as the major product.
Hückel and Möbius molecular orbital theories take center stage here. You need to be fluent in: (e.g., [4+2] Diels-Alder) Electrocyclic Reactions: (Ring closing/opening)