The following technical report is available from http://aib.informatik.rwth-aachen.de: CD2Alloy: A Translation of Class Diagrams to Alloy Oliver Kautz, Shahar Maoz, Jan Oliver Ringert, and Bernhard Rumpe AIB 2017-06 This report presents a translation from UML class diagrams [OMG15, Rum16] to Alloy modules [Jac06] and a translation from Alloy instances back to UML object diagrams. An overview of the translation was first presented in [MRR11a] and applied in [MRR11b] to semantic differencing of class diagrams. It supports an extended list of CD language features, including, e.g., directed associations, composite aggregations, interfaces, multiple inheritance, and enumerations. The translation thus supports essential features of many real-world CDs, UML and EMF metamodels, practically not analyzable before. An important feature of the translation is the ability to analyze multiple class diagrams within one Alloy module, which is not possible with previous translations. This document defines the translations by translation rules that operate on the abstract syntax of a class diagram language and produce concrete syntax of the Alloy language. We give examples showing class diagrams and complete representations in Alloy as well as an Alloy instance and its object diagram representation.