8.27This reaction has been reported in the chemical literature and proceeds as shown (91% yield):Notice that the configuration of the product is the sameas the configuration of the reactant. This isbecause the stereogenic center is not involved in the reaction. When we say that SN2 reactions pro-ceed with inversion of configuration we refer only to the carbon at which substitution takes place,not a stereogenic center elsewhere in the molecule.\8.28(a)The starting material incorporates both a primary chloride and a secondary chloride. Thenucleophile (iodide) attacks the less hindered primary position.(b)Nucleophilic substitution of the first bromide by sulfur occurs in the usual way.The product of this step cyclizes by way of an intramolecular nucleophilic substitution.(c)The nucleophile is a dianion (S2). Two nucleophilic substitution reactions take place; the sec-ond of the two leads to intramolecular cyclization.
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