16836-28-5

Upstream product

• 30211-82-6 ent-17-acetoxy-16β-hydroxykauran-3-one 
• 20460-65-5 ent-kaurene-16-en-3-one 
• 548486-51-7 (16R)-16,17-epoxy-ent-kauran-3-one 
• 30256-96-3 (16R)-16-hydroxy-17-{[(4-methylphenyl)sulfonyl]oxy}-ent-kauran-3-one 
• 19891-40-8 ent-3β-hydroxykaur-16-ene 
• 38602-53-8 (16R)-16,17-dihydroxy-ent-kauran-3-one 

Downstream Products

• 16836-28-5 ent-16,17-dihydroxy-16β-kauran-3-one 
• 19891-29-3 C₂₀H₃₄O₃ 
• 30256-96-3 (16R)-16-hydroxy-17-{[(4-methylphenyl)sulfonyl]oxy}-ent-kauran-3-one 

Relevant academic research and scientific papers

Sesquiterpenes and phenolic compounds from achillea clypeolata

The investigation of a dichloromethane extract of flower heads of Achillea clypeolata collected in Bulgaria led to the isolation of one guaiane (4,10,11-trihydroxy-guaiane, 1), four eudesmanes (4(15)-eudesmene-1β, 11-diol, 2, clypeotriol, 3, 3-epi-clypeotriol, 4, cryptomeridiol, 5), one diterpene (sugeroside, 6) and two phenolic compounds (centaureidin, 7 and scopoletin, 8). Their structures were elucidated by UV/vis, EI- and CI-MS as well as by one- and two-dimensional NMR experiments. 4,10,11-Trihydroxy-guaiane (1) and 3-epi-clypeotriol (4) are reported here for the first time.

Chemical transformations of phyllocladane (=13β-kaurane) diterpenoids

Earlier phytochemical work on Plectranthus ambiguus (Lamiaceae) afforded a series of tetracyclic phyllocladane-type (=13β-kaurane) diterpenoids (see 1a-f). In the course of investigations concerning the reaction behavior of this rare natural-products, a new constituent of P. ambiguus was isolated, (2S,3R,16R)-phyllocladane-2,3,16,17-tetrol 2,3-diacetate (1g), and another eighteen new phyllocladanes were prepared by chemical transformations and characterized. The main constituent 1b of P. ambiguus was chemically transformed to the known natural diterpenoid calliterpenone (=(16R)-16,17-dihydroxyphyllocladan-3-one; 2) thus unambiguously establishing its structure (Scheme 1). Epimerization at C(16) via the epoxy derivative 20 yielded 16-epicalliterpenone (21), 17-hydroxyphylloclad-15-ene-3-one (22), and (16R)-3-oxophyllocladan-17-al (23) (Scheme 6). Comparing this reaction sequence with the corresponding one starting from diastereoisomeric (16R)-16,17-dihydroxy-ent-kauran-3-one (=abbeokutone; 27) showed basically the same outcome (Scheme 7). Furthermore, three new C(16)-substituted ent-kauran-3-ones were characterized. Reliable spectroscopic arguments for the determination of the configuration at C(16) in phyllocladanes and kauranes as well as for the differentiation of the diastereoisomeric skeletons are presented.

GUAIANOLIDES AND HELIANGOLIDES FROM HYMENOPAPPUS NEWBERRYI

The aerial parts of Hymenopappus newberryi afforded two heliangolides, two thymol derivatives, as well as two new guaianolides and a trans,trans-germacranolide closely related to hiyodorilactone A.Furthermore, the ent-kaurene derivative abbeokutone was present.These results are of chemotaxonomic interest.Key Word Index - Hymenopappus newberryi; Compositae; sesquiterpene; lactones; guaianolides; heliangolides; ent-kaurene derivative; chemotaxonomy.