Govt. Exams
Entrance Exams
2-methylbut-2-ene: (CH3)2C=CH-CH3. Ozonolysis cleaves the C=C to give (CH3)2C=O (acetone) and CH3-CHO (acetaldehyde). Two different organic products are formed.
In Williamson ether synthesis, the alkoxide ion attacks via SN2 mechanism, which prefers primary alkyl halides due to less steric hindrance. Tertiary substrates don't react due to steric hindrance.
Vicinal coupling (3J) between protons separated by 3 bonds typically has values of 6-18 Hz, with typical values around 7-8 Hz for anti-periplanar and 2-5 Hz for gauche conformations.
PCC is a mild oxidizing agent that oxidizes primary alcohols to aldehydes without further oxidation to carboxylic acids (unlike acidic KMnO4 or K2Cr2O7).
SN2 reactions proceed fastest with primary alkyl halides due to minimal steric hindrance around the carbon bearing the leaving group. CH3CH2Br (primary) > CH3CHBrCH3 (secondary) > (CH3)3CBr (tertiary).
The methyl group is electron-donating through inductive and hyperconjugative effects, making the benzene ring more electron-rich. This activates the ring for EAS and directs incoming electrophiles to ortho and para positions.
Friedel-Crafts alkylation using CH3Cl with AlCl3 as Lewis acid catalyst converts benzene to toluene. This is the standard industrial method for alkylbenzene synthesis.
In staggered conformation, bonds are maximally separated reducing electron-electron repulsion and torsional strain. Staggered is most stable with ~12 kJ/mol lower energy than eclipsed.
Lucas reagent (HCl + ZnCl2) forms turbidity with primary alcohols immediately, secondary alcohols after 5 minutes, and tertiary alcohols instantly with dehydration.
The structure has 5 carbons with main chain having OH at position 1 and two methyl groups at position 2. IUPAC name is 2,2-dimethyl-1-propanol.
