Abstract: Recently, 13-hydroxy-α-eudesmol 1a was first isolated from C. uncata Cunn. by King and Robinson et aL and its structure was determined by high field NMR techniques, however, the absolute configuration of C-11 remained unsolved. Herein, we report the first total synthesis and determination of the stereochemistry of 13-hydroxy-α-eudesmol. In our synthesis (+)-α-selinene has also been accomplished.