13C NMR chemical shifts of ovalifoliene and related compounds with the 2,3-seco-alloaromadendrane skeleton: Structure of (+)-9α-acetoxyovalifoliene, a plant growth inhibitor

13C NMR spectra of several 2,3-seco-alloaromadendrane-type acetyl hemiacetals were analysed and the structure of an additional plant growth-inhibitor was determined to be (+)-9α-acetoxyovalifoliene. The biological activity of the new compound is also described.