seco-Hinokiol, a new abietane diterpenoid from Rosmarinus officinalis.

ABSTRACT

seco-Hinokiol (1), a new abietane diterpenoid, has been isolated from the leaves of Rosmarinus officinalis. Its structure was elucidated on the basis of extensive spectroscopic analysis. To our knowledge, this is the fourth report of a seco-abietane having been isolated. In addition, methyl carnosate (4) was synthesized from carnosic acid (3), and detailed NMR spectroscopic data are provided to clarify previous literature reports.