Work backward to an appropriate organozinc halide and organohalide to make the bonds indicated by the blue arrows. There may be two possibilities for each.
(a)

Verified step by step guidance

1. Identify the bond indicated by the blue arrow. This bond is between the cyclohexene ring and the pyridine ring.
2. To work backward, consider the retrosynthetic analysis. Break the bond at the blue arrow to form two fragments: one containing the cyclohexene ring and the other containing the pyridine ring.
3. For the cyclohexene fragment, consider it as an organozinc halide. This means replacing the bond with a zinc halide group, such as ZnBr.
4. For the pyridine fragment, consider it as an organohalide. This means replacing the bond with a halogen, such as Br.
5. Alternatively, reverse the roles: consider the pyridine fragment as the organozinc halide and the cyclohexene fragment as the organohalide. This provides the second possibility for the synthesis.

Key Concepts

Organozinc Reagents

Organozinc reagents, such as RZnX, are organometallic compounds where a carbon atom is bonded to zinc. They are highly reactive and can act as nucleophiles in organic reactions, particularly in coupling reactions. Understanding their reactivity and how they can form carbon-carbon bonds is essential for synthesizing complex organic molecules.

Organohalides

Organohalides are organic compounds containing at least one halogen atom (F, Cl, Br, I) bonded to a carbon atom. They serve as important intermediates in organic synthesis, often undergoing nucleophilic substitution or elimination reactions. Recognizing the structure and reactivity of organohalides is crucial for designing synthetic pathways.

Nucleophilic Substitution Reactions

Nucleophilic substitution reactions involve the replacement of a leaving group (such as a halide) by a nucleophile. These reactions can proceed via two main mechanisms: SN1 (unimolecular) and SN2 (bimolecular). Understanding these mechanisms helps predict the outcome of reactions involving organohalides and organozinc reagents, which is key to constructing the desired molecular structures.