In 2016 Rossin et al. reported the synthesis of the first difunctionalized cis-cyclooctene (CCO) with an allylic moiety in seven steps starting from cis,cis-1,5-cyclooctadiene (1,5-COD, Figure ). The authors reported the formation of a mixture of the axial and equatorial difunctionalized TCO derivatives after isomerization with UV-light and a sensitizer as described by the Fox group (Figure ). Currently, the synthetic accessibility of the most commonly used difunctionalized TCOs with releasing properties is rather problematic, mainly due to low yielding steps and a lengthy overall synthesis. Ideally, a TCO should have multiple orthogonal handles, a fast click reaction with a tetrazine and a rapid release functionality. In comparison with the difunctionalized TCO of Rossin et al., a shorter and higher yielding synthesis method of a TCO with similar properties is desired. Herein, we present the straightforward synthesis of a strained and allylic functionalized TCO with two orthogonal handles in only four steps starting from readily available 1,5-COD (Figure ). After separation, both the endo-and exo-diastereomers were diastereoselectively functionalized at the allylic position prior to the photochemical isomerization step of the cisdouble bond. A recent continuous flow isomerization method including an aqueous extraction to separate the cis-and trans-cyclooctynes, developed by Blanco et al. was employed in this work, facilitating the scalability of this pathway. Functionalized derivatives of the TCO were evaluated for their releasing capabilities. This method represents a major step forward in the ease and efficiency of the synthesis of releasing TCOs.