Pls use C S Toh's guide book with caution. It is barely enough to get you a high B. It is an outdated book which needs updating.
It was written for the 2007 chem syllabus, which was not as demanding as the 2010-2014 syllabus.
Even some neighbourhood JC's lecture notes are insufficient for 2013- 2014 syllabus,as examiners used concepts and questions from first year university textbooks in 2010-2012 exam papers.
The bar has been raised.
To secure a good A grade, you need to read organic chemistry university textbooks.
It is highly concise and good for test revision. It is up to date.
However, Cambridge operates without a syllabus and extends concepts to university level in their recent exam papers.
Or you may source for top JC lecture notes, which have more information.