Two New Sesquiterpenes and Two New Lignans from the Leaves of Juniperus Chinensis Var. Kaizuka

Abstract

Two new sesquiterpenes, 8,9‐secocedrachinol (1), (+)‐1‐hydroxy‐1,3,5‐bisabolatrien‐10‐one (2) and two new lignans, (7R,8S)‐9′‐(β‐rhamnopyranosyl)‐3‐methoxy‐3′:7,4′:8‐diepoxyneolignan‐4,9‐diol (3), and (7S,8S)‐9′‐(β‐rhamnopyranosyl)‐3‐methoxy‐3′:7,4′:8‐diepoxyneolignan‐4,9‐diol (4), together with eleven known compounds, cedral, sesquichamaenol, caryophylleneoxide, humulenepoxide, benzoic acid benzylester, 4‐hydroxy‐3‐methoxycinnamic acid, 7‐hydroxy‐8‐(3‐methylbut‐2‐enyl)chromen‐2‐one, 2‐[4‐(3‐ hydroxy propyl)‐2‐methoxyphenoxy]propane‐1,3‐diol, luteolin, 3,4‐bis‐(4‐hydroxy‐3‐methoxybenzyl)dihydro‐ furan‐2‐one, and pluviatolide were isolated from the leaves of Juniperus chinensis var. kaizuka. The structures of these compounds were established on the basis of spectroscopic data.

Enantioselective Synthesis of the Bisabolane Sesquiterpene (+)-1-Hydroxy-1,3,5-Bisabolatrien-10-one and Revision of its Absolute Configuration

“…To this end, circular dichroism study, some biosynthetic considerations, and comparison of the optical rotation sign with those of structurally similar terpenes might help in the tentative assignation of the configuration. This is the case with 1-hydroxy-1,3,5-bisabolatrien-10-one (1) ( Figure 1) whose enantiomeric forms were both isolated [2,3] from Juniperus species. More specifically the levorotatory isomer was extracted from J. formosana heartwood [2], whereas the opposite enantiomer was isolated from the leaves of J. chinensis [3].…”

“…More specifically the levorotatory isomer was extracted from J. formosana heartwood [2], whereas the opposite enantiomer was isolated from the leaves of J. chinensis [3]. On the basis of biosynthetic considerations the absolute configuration of the ()-isomer [2] was assigned as (S), whilst other authors [3] left unassigned that of the (+)-enantiomer.…”