This unique textbook provides new guidelines for "biocatalytic retrosynthesis" in which molecules are disconnected with consideration for applying biocatalysts in the forward synthesis direction. It aims to enable students to make the connection between biocatalysis and synthesis earlier in their studies and to equip students for the modern world of organic synthesis where biocatalysts play an increasingly important role. Tutorials enable the reader to practise disconnecting target molecules to find the 'hidden' biocatalytic reactions which can be applied in the synthetic direction. It also contains a complete description of the current biocatalyst classes that are available. This textbook is an essential resource for lecturers and students studying synthetic chemistry. It also serves as a handy reference for practising chemists wishing to embed biocatalysis into their synthetic toolbox.