70477-26-8Relevant academic research and scientific papers
New naphthopyranone glycosides from Paepalanthus vellozioides and Paepalanthus latipes
Vilegas, Wagner,Dokkeddal, Anne Ligia,Piacente, Sonia,Rastrelli, Luca,Pizza, Cosimo
, p. 746 - 749 (1999)
Three new compounds - 3,4-dihydro-10-hydroxy-7-methoxy-3-(R)-methyl-1H- 3,4-dihydronaphtho-]2,3c]-pyran-1-one-9-O-β-D-glucopyranoside (1), 3,4- dihydro-10-hydroxy-7-methoxy-3-(R)-methyl-1H-3,4-dihydronaphtho-[2,3c]- pyran-1-one-9-O-β-D-glucopyranosyl-(1→6)-glucopyranoside (2), and 3,4- dihydro-10-dihydroxy-7-methoxy-3-(R)-methyl-1H-3,4-dihydronaphtho-[2,3c]- pyran-1-one-9-O-β-D-allopyranosyl (1→6) glucopyranoside (3) - were isolated from the leaves of Paepalanthus vellozioides and Paepalanthus latipes and characterized by spectrometric methods, mainly electrospray mass spectrometry and 1D and 2D NMR experiments. These unusual glycosylated dihydronaphthopyranones may serve as taxonomic markers of the genus Paepalanthus, since these compounds were not detected in other genera belonging to the Eriocaulaceae family.
Total synthesis and confirmation of the absolute stereochemistry of semiviriditoxin, a naphthopyranone metabolite from the fungus Paecilomyces variotii
Tan, Nichole P.H.,Donner, Christopher D.
experimental part, p. 4007 - 4012 (2009/09/30)
The first total synthesis of (S)-semiviriditoxin 2 is described. The approach utilizes a tandem Michael-Dieckmann reaction between ortho-toluate 5 and dihydropyran-2-one 6 to construct the naphthopyranone core, the dihydropyran-2-one 6 being prepared from (R)-1,2-epoxy-4-butanol. Spectroscopic comparison of synthetic (S)-semiviriditoxin 2 with (R)-semivioxanthin 3, prepared in four steps from (R)-propylene oxide, confirmed the (S)-stereochemistry of natural semiviriditoxin from Paecilomyces variotii. Crown Copyright
Total synthesis of (R)- and (S)-semi-vioxanthin
Drochner, Daniel,Müller, Michael
, p. 211 - 215 (2007/10/03)
Compounds (R)- and (S)-semi-vioxanthin 2 were synthesized by a tandem Michael reaction of orsellinate 3 and the chiral Michael acceptors 4. The key step for the formation of lactone (R)-4. is a regio- and enantioselective, enzyme-catalyzed reduction of tert-butyl 3,5-dioxohexanoate (5) by an alcoholdehydrogenase from Lactobacillus brevis. Compound (S)-4 was synthesized by the Claisen condensation of tert-butyl acetate and ethyl (S)-3-hydroxy-butanoate (8). Cleavage of the benzyloxymethyl groups in the protected (R)- and (S)-semi-vioxanthins was achieved by hydrogenolysis to afford (R)-2 and (S)-2, respectively.
Synthesis of Semivioxanthin via a Polyketide
Yamaguchi, Masahiko,Okuma, Tadashi,Nakamura, Shigeo,Minami, Toru
, p. 183 - 185 (2007/10/02)
The first synthesis of semivioxanthin has been achieved via the intermediate 3,5,7,9,11-pentaoxo-tridecanedioate one of whose ketone groups was protected as a ketal of o-phenylenedimethanol.
