Question

1. Name these compounds according to the IUPAC system Include stereochemistry (cis/trans, E/Z) where shown. 4 Write "most" under the alkene which is most stable. Write "least" under the alkene which is least stable. 3. Write in the product of this reaction: HBO HBr

Answer 1

• e © compound has E stereo chemistry We choose longest parental chain having the functional group nearest: longest chain containing 7 carbon IUPAC Name: - (E) -2-chloro-495-dimethylhept-2-ehe. CA : Double bond has higher priority than halogens (According to IUPAC) 3 IUPAC Name:- (2),(2)-3-bromo-3-chlorowyclohexa-14-diene (since molecule in cyclic & having & carbon in parental chain : word "Cyelo hexe a" is used) (A) (B) Stability of alkenes are determined by the substitution across the double bond Higher the substitution across 18 the double bond, greater be the stability of albene. In compound (A), there are two substitutio, in compound (B), three (3) substitution { in Compound (6) mly one substitution across the double bond. u stability order (Most stable) (Least stable)

③ i I Hors . I This is the example of addition reaction across the double bond first of all, double bond acts as nucleophile & attacks into HBr & addition of proton gives steuble carbocation intermediate. ( carbocation order 372 > 10) HBO Or I -B (3 carbocation) (g° carbocation) (More stable) less stable) Now Bro attacks into the more stable carbocation- intermediate Tot + Bo - Lor HBY This geen is similar to the above sets. By following the same mechanism te formation of most stable carbocation intermediate followed by the addition of bromide (Bg) im gives the desired product. ko