Diterpenoids from the leaves of Juniperus chinensis var. kaizuka.

Two diterpenoids based on novel carbon skeletons, namely, 8,19-dioxo-8,14-seco-chinan-14,11-olide (1) and 8-oxo-8,14-seco-abiet-12-en-14,19-dial (2), have been isolated, together with two new abietane diterpenoids, 13 beta,14 beta-epoxyabiet-7-en-19,6 beta-olide (3) and 7 beta-hydroxyabieta-8,11,13-trien-19-al (4), from the leaves of Juniperus chinensis. Their structures were determined by spectroscopic methods, including 2D NMR, and, in the case of 1, X-ray crystallographic analysis.