Zobrazeno 1 - 10
of 131
pro vyhledávání: '"Nicon Ungur"'
Autor:
Olga Morarescu, Marionela Traistari, Alic Barba, Gheorghe Duca, Nicon Ungur, Veaceslav Kulcițki
Publikováno v:
Chemistry Journal of Moldova: General, Industrial and Ecological Chemistry, Vol 16, Iss 1, Pp 99-104 (2021)
The selective one-step synthesis of 13-epi-manoyl oxide is reported based on a low-temperature superacidic cyclization of sclareol. The reaction conditions have been finely tuned in order to achieve a 9:1 ratio between epimeric oxides in favor of the
Externí odkaz:
https://doaj.org/article/fe9885feccab43f8b2b1936d67131a1f
Publikováno v:
Marine Drugs, Vol 19, Iss 11, p 636 (2021)
Scalarane sesterterpenoids emerged as interesting bioactive natural products which were isolated extensively from marine sponges and shell-less mollusks. Some representatives were also reported recently from superior plants. Many scalarane sesterterp
Externí odkaz:
https://doaj.org/article/22c9071ad0a54a288f90c455743d6243
Autor:
Elena Pruteanu, Vladilena Gîrbu, Nicon Ungur, Leentje Persoons, Dirk Daelemans, Philippe Renaud, Veaceslav Kulcițki
Publikováno v:
Molecules, Vol 26, Iss 15, p 4549 (2021)
A convenient strategy for molecular editing of available ent-kauranic natural scaffolds has been developed based on radical mediated C–C bond formation. Iodine atom transfer radical addition (ATRA) followed by rapid ionic elimination and radical az
Externí odkaz:
https://doaj.org/article/3cbb2b79b59a4756a39145b573207eae
Publikováno v:
Chemistry Journal of Moldova: General, Industrial and Ecological Chemistry, Vol 8, Iss 2, Pp 94-100 (2013)
Synthesis of polyfunctional triterpene derivative [8(27),13E,17E,21E]-15-phenylsulfonyl-16-oxobicyclofarnesylfarnesol benzyl ether (8) from commercially available monoterpene geraniol and diterpene manool has been accomplished in 73% yield and its
Externí odkaz:
https://doaj.org/article/a6d26e7982324ae7a6a5d1f5509ac66a
Publikováno v:
Chemistry Journal of Moldova: General, Industrial and Ecological Chemistry, Vol 8, Iss 2, Pp 90-93 (2013)
The content of known tetra- and pentacyclic diterpenoids in extracts of sunfl ower (Helianthus annuus L.) dry wastes has been studied using different solvents for extraction. It was established that the largest extracted quantity of ent-kaur-16-en-
Externí odkaz:
https://doaj.org/article/7a97851aeb724b4fbd9f560ff9b6775c
Autor:
Nicon Ungur
Publikováno v:
Chemistry Journal of Moldova: General, Industrial and Ecological Chemistry, Vol 6, Iss 2, Pp 30-35 (2011)
The paper presents an outline of the synthesis of some natural terpenoids of marine origine having diverse carbocyclic skeletons: labdanic, isocopalic, scalaranic, cheilanthanic, drimanic, sacculatanic. Schemes – 6, figures - 2. Bibliographic refer
Externí odkaz:
https://doaj.org/article/cf559be614694ea0a715dfdb4dc585fd
Publikováno v:
Chemistry Journal of Moldova: General, Industrial and Ecological Chemistry, Vol 5, Iss 2, Pp 68-72 (2010)
The methods of thermogravimetry (TGA) and differential scanning calorimetry (DSC) have been used to study the thermal and thermo-oxidative degradation of polystyrene (PS) and a PS-clay nanocomposite. An advanced isoconversional method has been applie
Externí odkaz:
https://doaj.org/article/0c46ec9c28ba48dfae4ea58231520421
Publikováno v:
Chemistry Journal of Moldova: General, Industrial and Ecological Chemistry, Vol 3, Iss 2, Pp 105-108 (2008)
A relatively simple method for isolation of the mixture of ent-kaur-16-en-19-oic (1) and ent-trachiloban-19-oic (2) acids from dry waste of sunflower processing has been elaborated, and it has been shown that the waste can serve as an accessible sour
Externí odkaz:
https://doaj.org/article/18beb58d491d4d6d9f50e0829cd219b1
Publikováno v:
Chemistry Journal of Moldova: General, Industrial and Ecological Chemistry, Vol 1, Iss 1, Pp 22-35 (2006)
A review of diterpenoid cyclization initiated by electrophilic reagents is provided. Conventional protonic and Lewis acids are examined along with superacids as initiators of cyclization cascade. An emphasis is placed on the use of cyclization reacti
Externí odkaz:
https://doaj.org/article/07232bd0dbe747829151692e343e1e15
Publikováno v:
Chemistry Journal of Moldova: General, Industrial and Ecological Chemistry, Vol 6, Iss 1, Pp 110-112 (2011)
A selective rearrangement of a epoxy-homodrimanic substrate is described. Using fluorosulfonic acid at low temperature leads by ring contraction to a perhydrindanic structure. On the contrary, using boron trifluoride-diethyl ether at r.t. selectively
Externí odkaz:
https://doaj.org/article/0313980b3f7947cfb9662e496ad3dd2e