The formation of an innumerable number of carbon compounds is due to its:

Total number of enol forms possible for the compound formed during the given reaction will be (including stereoisomers):
$CH_3MgBr + CH_3CH_2COCl \to$

Product $(A)$ is

Which of the following compounds shall not produce propene by reaction with $HBr$ followed by elimination or direct only elimination reaction?

Which of the following is among the major products of the reaction of $(E)-3$-methylpent$-2$-ene with $BH_3$ in $THF$ followed by the addition of $H_2O_2/HO^{-}$?

Which of the following substituted benzene derivatives would furnish three isomers in significant amount when one more substituent is introduced: