Spatial structure of isoepoxyestafiatin

The spatial structure of the sesquiterpene lactone isoexpoxyestafiatin has been established by the x-ray method as 1,10ß;3,4-diepoxy-5,7,6H-11(13)en-6,12-olide.Translated from Khimiya Prirodnykh Soedinenii, Vol. 33, No. 1, pp. 66–67, January–February, 1997.     

Synthesis and crystal structure of (4S,5R)-2-[2-(hydroxyethyl)imino]-3,4-dimethyl-5-phenyl-1,3-thiazolidine

Acid hydrolysis of l-N-[N′-(2-vinyloxy)ethylcarbamothioyl]ephedrine was studied. The synthesized (4S,5R)-2-[2-(hydroxyethyl)imino]-3,4-dimethyl-5-phenyl-1,3-thiazolidine was studied by means of X-ray diffraction.     

Reactions at the double bond in the epoxy group of arglabin

The interaction of arglabin, a sesquiterpene lactone of the guainane type, with peracetic acid and hydrogen chloride has been investigated. This led to the synthesis of nine compounds the structure of which have been established in the basis of spectral characteristics (IR, PMR, and mass spectra). The structures and absolute configurations of the molecules of 3,10-dichloro-1,4-dihydroxy-and 10-chloro-1-hydroxy-3,4-epoxyarglabins have been determined as 3R, 10R-dichloro-1R,4R-dihydroxy-5S,6S,7S-trans-trans-guai-11(13)-en-6,12-olide and 10R-chloro-1R-hydroxy-3S,4R-epoxy-5S,6S,7S-trans-trans-guai-11(13)-en-6,12-olide, respectively.Institute of Organic Synthesis and Coal Chemistry, Academy of Sciences of the Kazakh SSR, Karaganda. A. N. Nesmeyanov Institute of Organometallic Compounds, Academy of Sciences of the USSR, Moscow. Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, Novosibirsk. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 33–42, January–February, 1991.     

Epoxidation of alantolactone and isoalantolactone

Alantolactone and isoalantolactone have been epoxidized with peracetic, m-chloroperbenzoic, and trifluoroperacetic acids. The structure of 4(15)--epoxyisoalactone has been established by an x-ray structural investigation.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 879–884, November–December, 1996. Original article submitted May 20, 1996.     

Pulchellin C and inuchinenolide C from Inula caspica

The pseudoguaianolide inuchinenolide C and the eudesmanolide pulchellin C have been isolated for the first time from the flower heads and leaves ofInula caspica Blume, and their spatial structures have been established by an x-ray structural experiment as 2,6-diacetoxy-6-hydroxy-1,7(H),8,10(H)-pseudoguai-11(13)-en-8,12-olide and 2,3-dihydroxy-5,7,8(H)-eudesma-4(15),11(13)-dien-8,12-olide, respectively.Institute of Organic Synthesis and Coal Chemistry, Academy of Sciences of the Kazakh SSR, Karaganda. A. N. Nesmeyanov Institute of Organometallic Compounds, Academy of Sciences of the USSR, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 748–757, November–December, 1990.