2-Chloropentane, isomers

Solution We are starting with n-pentane, so we do not need to worry about any branched chain structures. In the chlorination reaction, a Cl atom replaces one H atom. There are three different carbons on which the Cl atom can be placed. Hence, three stmctural isomers of chloropentane can be derived from n-pentane ... 

The activation of chloroalkanes proceeds exclusively at the terminal methyl groups, with no evidence for oxidative addition of the C-Cl bonds. In the case of 2-chloropentane, for which two isomers (2-chloro, and 4-chloro) might be anticipated, only the latter (410) is obtained, as a mixture of two diastereoisomers. " It was concluded that the 2-chloro-isomer does form, but undergoes spontaneous j5-chloride elimination to afford Tp RhHCl(CNCH2 Bu) (422), obtained as a by-product (28%), and pent-l-ene. This is supported by the observation that UV irradiation of 395 in 2-chloropropane affords only 422 and Tp RhCl2 (CNCH2 Bu) (373). 

Chlorination of (S)-2-chloropentane produces a mixture of isomers with molecular formula C5H10CI2. How many isomers are obtained (consider stereoisomers as separate products) Draw all of the products. 

Assume that you have carried out a radical chlorination reaction on (Jl)-2-chloropentane and have isolated (in low yield) 2,4-dichloropentane. How many stereoisomers of the product are formed and in what ratio Are any of the isomers optically active (See Problem 10.32.)... 

---