Absolute Configuration of -Perhydroazulene.

We present the absolute configuration (AC) determination of an alkane, -perhydroazulene (), that displays the naturally very common trans fused [5,7] ring system. We outline the first synthesis yielding enantiopure and the application of optical rotatory dispersion (ORD) and vibrational circular dichroism (VCD) techniques. The spectroscopic results are in excellent agreement with the computed ORD at B3LYP/6-311++G(2d,2p) and the computed VCD spectrum at B3LYP/6-311++G(d,p), providing an assignment of the AC as (,)-(+)-.