Canataxpropellane belongs to the medicinally important taxane diterpene family. The most prominent congener, Taxol, is one of the most commonly used anticancer agent in clinics today. Canataxpropellane exhibits a taxane skeleton with three additional transannular C-C bonds, resulting in a total of six contiguous quaternary carbons, of which four are located on a cyclobutane ring. Unfortunately, isolation of canataxpropellane from natural sources is inefficient. Here, we report a total synthesis of (-)-canataxpropellane in 26 steps and 0.5% overall yield from a known intermediate corresponding to 29 steps from commercial material. The core structure of the (-)-canataxpropellane (2) was assembled in two steps using a Diels-Alder/ortho-alkene-arene photocycloaddition sequence. Enantioselectivity was introduced by designing chiral siloxanes to serve as auxiliaries in the Diels-Alder reaction.