NEET UG 2021 — Chemistry Organic Chemistry

$2$2 -bromopentane gives $2$2 -pentene as the major product according to Saytzeff's rule as it is more substituted alkene

$${\mathrm{CH}}_{3}-\mathrm{CHBr}-{\mathrm{CH}}_{2}-{\mathrm{CH}}_{2}-{\mathrm{CH}}_{3}\overset{\mathrm{alc}.\mathrm{KOH}}{\rightarrow }{\mathrm{CH}}_{2}=\mathrm{CH}-{\mathrm{CH}}_{2}-{\mathrm{CH}}_{2}-{\mathrm{CH}}_{3} (\mathrm{Hofmann}\mathrm{product},\mathrm{least}\mathrm{substituted}\mathrm{alkene})$$CH3​−CHBr−CH2​−CH2​−CH3​→alc.KOHCH2​=CH−CH2​−CH2​−CH3​(Hofmannproduct,leastsubstitutedalkene)

$${\mathrm{CH}}_{3}-\mathrm{CHBr}-{\mathrm{CH}}_{2}-{\mathrm{CH}}_{2}-{\mathrm{CH}}_{3}\overset{\mathrm{alc}.\mathrm{KOH}}{\rightarrow }{\mathrm{CH}}_{3}-\mathrm{CH}=\mathrm{CH}-{\mathrm{CH}}_{2}-{\mathrm{CH}}_{3} (\mathrm{Satzeff}'s\mathrm{product},\mathrm{more}\mathrm{substituted}\mathrm{alkene})$$CH3​−CHBr−CH2​−CH2​−CH3​→alc.KOHCH3​−CH=CH−CH2​−CH3​(Satzeff′sproduct,moresubstitutedalkene)