The present title "Organic Reaction" has been designed for under-graduate and post-graduate student of all Indian universities. We live and breed in a world that owes to organic chemistry many times more than organic chemistry owes to it. The domain of organic chemistry is so enormous that it defies the imagination of any individual, let alone mastering it is entirety. This is not a text book, but a reference book supplement to the text of organic chemistry meant for university students. However some advanced students may find the book inadequate.