Structure of 7-hydroxy-lathyrol a further diterpene from euphorbia lathyris L.

Macrocyclic Lathyrane Type Diterpene Esters (Jolkinols) from Callus Cultures and Roots ofEuphorbia lathyris

“…Obviously, the protons of the methyl group substituting the cyclopropane ring at the (3-side of the molecule (CH3-19) are sterically close to the aromatic ring of the benzoyloxy group in compound A' which causes this unusual shielding effect. Similar diamagnetic shifts caused by aromatic ring structures have also been reported for the protons of acetyl groups in a 7-hydroxylathyrol ester (13) and in a limonoid compound isolated from a Guarea species (14).…”

A Novel Lathyrane Diterpenoid from the Roots of Euphorbia lathyris

“…The identical configuration of C-5 was found in lathyrane ester L 9 , jolkinol B, and 15 -Obenzoyl-5R-hydroxyisolathyrol, 8,11,12 and the opposite configuration in esters L 1 , L 2 , and L 7b . [5][6][7] Our findings support the suggestion of Manners and co-workers that lathyrane and related jatrophane diterpenes should be stereochemically similar and that a stereochemical reexamination of some lathyrane diterpenes is necessary. 13 The demonstrated enolic form of compound 1 is presumably stable because of hydrogen bonding, which can exist between the 14-keto group and OH-12 and OH-15.…”

Diterpenoids from Euphorbia pithyusa subsp. cupanii

“…9 Yet, their detection in 1c stands in sharp contrast to what was observed during the hydrolysis of the 7-hydroxylathyrol ester Euphorbia factor L 2 (3a). 10 In this case, no significant change was observed for J 4,5 , while the chemical shift of the allylic methyl was moved upfield (∆δ -0.16, CDCl 3 ) and H-12 underwent a downfield shift (+ 0.43 ppm, CDCl 3 ) (Table 1). As a result of opposite shifts compared to their esters, overall differences of almost 1 ppm (δ 6.04 vs 6.98, CDCl 3 ) for the signal of H-12, and of almost 0.30 ppm (δ 1.99 vs 1.71, CDCl 3 ) for the signal of the allylic methyl were observed between lathyrol (1c) and its 7-hydroxy derivative (3b) (Table 1).…”