Schinortriterpenoids, such as pre-schisanartanin A and arisanlactone C, are complex highly oxygenated polycyclic terpenes. In this study, the left-hand fragment of class terpenes, which possesses oxygen-functionality at C19, was synthesized through [3+2] cycloaddition with excellent diastereoselectivity. This stereoselectivity investigated by computational studies. Further selective transformat...