Chemistry - Organic Synthesis Notation - Education Scotland：化学，有机合成符号-苏格兰教育.doc

NATIONAL QUALIFICATIONS CURRICULUM SUPPORT Chemistry Organic Synthesis Notation [REVISED ADVANCED HIGHER] The Scottish Qualifications Authority regularly reviews the arrangements for National Qualifications. Users of all NQ support materials, whether published by Education Scotland or others, are reminded that it is their responsibility to check that the support materials correspond to the requirements of the current arrangements. Acknowledgement ? Crown copyright 2012. You may re-use this information (excluding logos) free of charge in any format or medium, under the terms of the Open Government Licence. To view this licence, visit .uk/doc/open-government-licence/ or e-mail: psi@.uk. Where we have identified any third party copyright information you will need to obtain permission from the copyright holders concerned. Any enquiries regarding this document/publication should be sent to us at enquiries@.uk. This document is also available from our website at .uk. Contents ‘Curly arrow’ notation 4 Bond fission 5 Homolytic fission 6 Heterolytic fission 8 Electrophiles and nucleophiles 8 Nucleophilic substitition 9 SN1 reaction mechanisms 10 SN2 reaction mechanisms 11 Organic synthesis notation The synthesis of organic molecules consists of the construction of compounds via organic reactions. Although some organic molecules can be simple to construct and design, some complex compounds can require many reaction steps to sequentially build the desired molecule. It is important that we can identify some steps common to most reactions and that we are able to represent these reactions in a manner that is recognised by most chemists. ‘Curly arrow’ notation All chemical reactions involve the breaking and making of bonds. The way that bonds break has an important bearing on the direction a reaction will take and on the mechanism of that reaction. In order to represent an organic reaction mechanism diagrammatically and to give an impression of bonds breaking and bonds b