
Subs. at any of the red C(s) will yield an equivalent structure.
Same goes fr the blue & green ones...
Q. as abv, no . of structural isomers of methyl anthracene is ___

Subs. at any of the red C(s) will yield an equivalent structure.
Same goes fr the blue & green ones...
wont isomers of methyl phenanthrene also be structural isomers of methyl anthracene ??

3 wud be the answer if v were asked the no. of mono-methyl derivatives of Anthracene.
But fr structural isomers toh phenanthrene waale bhi honge, n there'll be lots of open chain structures with their chain isomerism also with the formula C14H9CH3 (100 unsaturation)......!!