17946-96-2Relevant articles and documents
Friedelane triterpenoids: Transformations toward A-ring modifications including 2-: Homo derivatives
Das, Jayanta,Sarkar, Antara,Ghosh, Pranab
, p. 6673 - 6688 (2018/05/07)
Friedelin and its derivatives, commonly known as friedelane triterpenoids, exhibit potential biological effects ranging from antimicrobial to anticancer to anti-HIV. To modify the A-ring of the pentacyclic triterpenoid, various transformative scopes have been utilized. Herein, some simple unprecedented transformative protocols have been accomplished towards furnishing 42 (25 new) A-ring modified pentacyclic friedelane triterpenoids. It is worth noting that the modifications include the all-new 2-homo derivatives. The one-pot BF3·OEt2-mediated oxidative transformation of friedelin to yield friedel-3-enol acetate as the major product was one of the key reactions. A group of isomeric A-ring modifications was produced on the basis of simple transformations on suitable friedelane-based molecules. The syntheses of the novel 2-homofriedelanes were envisioned from the transformative reactions of the designed triterpenoid 3-chlorofriedel-2-ene-2-carbaldehyde, which was isolated as the major product from the reaction of friedelin with the novel Vilsmeier-Haack reagent. New A-ring modified derivatives were also obtained due to further interesting transformations of 3-chlorofriedel-3-ene, isolated as side products from the same reaction. Again, considering the scope of the 3-chloro-2-enal moiety associated with the A-ring of the triterpenoid, some heterocycle-linked- (bonded to C3) 2-homofriedelane triterpenoids were synthesized. Various common reaction strategies were employed on suitable substrates to finally achieve a series of C2,C3-; C3,C4- and C2,C3,C4-functionalized as well as 2-homofriedelane triterpenoids with just one to four efficient steps.
Synthetic secofriedelane and friedelane derivatives as inhibitors of human lymphocyte proliferation and growth of human cancer cell lines in vitro
Moiteiro,Justino,Tavares,Marcelo-Curto,Florencio,Nascimento,Pedro,Cerqueira,Pinto
, p. 1273 - 1277 (2007/10/03)
Controlled silylation of friedelin (1) from cork smoker wash solids, a byproduct generated during processing of corkboard by steam baking, gave 3-trimethylsiloxyfriedel-2-ene (3) in high yields. Oxidation of 3 with OsO4/NMMO produced 2α-hydroxyfriedelan-3-one (cerin) (5), from which the new 2,3-secofriedelan-2-al-3-oic acid (6) was obtained quantitatively by periodic acid oxidation. Oxidation of 3 with DDQ afforded friedel-1-en-3-one (8). Reductive ozonolysis of 3 gave 2α,3β-dihydroxyfriedelane, pachysandiol A (7). Compound 6 proved to be a potent inhibitor of human lymphocyte proliferation (IC50 = 10.7 μM) and of the growth of a human cancer cell line (GI50 = 5.4-17.2 μM). 13C NMR data for compounds (3, 4, 5, 6a, 7, and 8) are described for the first time.
Molecular rearrangements of D:A-friedoolean-2α,3α-epoxide
Mukherjee, J.,Banerjee, Reena,Sayeed, Abu
, p. 838 - 842 (2007/10/02)
The action of aq. perchloric acid, boron trifluoride etherate in benzene and dry hydrogen chloride in chloroform on D:A-friedoolean-2α,3α-epoxide (1) has been extensively studied.Action of aq. perchloric acid on 1 leads to the formation of a hydrocarbon (IV) and the expected diol (V).Action of boron trifluoride etherate in dry benzene on 1 affords an unsaturated alcohol (VII) whereas action of dry hydrogen chloride gas on 1 in chloroform results in the hydocarbon IV.
Acetoxylation of friedelin by lead (IV) acetate and anti-octant behaviour of 2-acetoxyketones
Dutta, G.,Bose, S. N.
, p. 975 - 977 (2007/10/02)
Four products have been isolated by boron trifluoride-catalysed lead (IV) acetate acetoxylation of friedelin.Three of them have been characterized as 2α-acetoxyfriedelin, 4α-acetoxyfriedelin and 2β, 4α-diacetoxyfriedelin.The former has been efficiently converted into pachysandiol-A.Chiroptical measurements (CD) of these 2-acetoxyketones show considerable antioctant behaviour.
