Synthese von rac‐Norartemeseol

Synthesis of rac‐Norartemeseol The synthesis of the terpenoid rac‐norartemesol (1b) is accomplished using epoxide ring‐opening reactions as key steps. Thus, addition of the thio‐substituted allyl anion 2b to ethylene oxide followed by proton‐induced cyclisation provides the tetrahydrofuran 4a. The oxirane 6, which is formed by simple functional group interconversion, is opened by the diethylaluminium salt 10 of a propargylsilane. After catalytic hydrogenation and tosylation, fluoride‐induced cyclisation of the allylsilane 13 gives the target molecule 1b.