HETEROCYCLES
An International Journal for Reviews and Communications in Heterocyclic ChemistryWeb Edition ISSN: 1881-0942
Published online by The Japan Institute of Heterocyclic Chemistry
Special Issue
Albert Eschenmoser's Special Issues,Vol. 82, No. 2, 2011
Published online: 26th October, 2010
■ Synthesis of 6-Deoxy-D-altrose Used as an Authentic Sample to Identify an Unknown Monosaccharide Isolated from the Fruiting Body of an Edible Mushroom
Masashi Yamada, Fumi Yoshida, Hiromune Ando, Hideharu Ishida,* Makoto Kiso, and Masakuni Tako
*Faculty of Applied Biological Sciences, Gifu University , 1-1 Yanagido, Gifu, Gifu 501-1193, Japan
Abstract
Here, we describe the synthesis of 6-deoxy-D-altrose and its subsequent use as an authentic sample to verify the structure of a monosaccharide newly isolated from the fruiting body of an edible mushroom. D-Rhamnopyranoside, converted from D-mannopyranoside, was selectively protected to give the 3-OH derivative, which was converted to the corresponding 6-deoxy-D-altropyranoside by nucleophilic substitution of the 3-triflate with acetoxy group. Removal of the protecting group, including the temporary protection of the anomeric position with the THP group, afforded the desired 6-deoxy-D-altrose. Both the NMR data and the [α]D value were identical to the data on the natural product, thus indicating that the recently isolated monosaccharide was 6-deoxy-D-altrose.
Published online: 19th October, 2010
■ Second Generation Palladium-Catalyzed Cycloalkenylation in Iridoid Lactone Synthesis: Total Syntheses of (±)-Onikulactone and (±)-Mitsugashiwalactone
Megumi Saeki and Masahiro Toyota*
*Department of Chemistry, Graduate School of Science, University of Osaka Prefecture, Sakai, Osaka 593-8531, Japan
Abstract
Type-II iridoid lactones, onikulactone (1) and mitsugashiwalactone (2), were synthesized by employing the second generation palladium-catalyzed cycloalkenylation reaction as the key step.
Published online: 11th November, 2010
■ Synthesis of Selenohydantoins from Isoselenocyanates and α-Amino Acids
Hajime Maeda,* Koichi Sakata, Masaru Takashima, Tatsuya Watanabe, Nobuteru Mizukami, Mitsunori Honda, and Masahito Segi*
*Chemistry Course, College of Science and Engineering, School of Chemistry, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan
Abstract
Selenohydantoins were synthesized by the reaction of isoselenocyanates with α-amino acids in high yields. Reaction of isoselenocyanates with β-amino acids gave a six-membered ring compound and acyclic selenoureas.
Published online: 30th September, 2010
■ Structures of Fukinone Epoxides. Configuration, Conformation, and CD Spectra
Yoshinori Saito and Motoo Tori*
*Faculty of Pharmaceutical Sciences, Tokushima Bunri University, 180 Nishihamabouji, Yamashiro-machi, Tokushima, 770-8514, Japan
Abstract
The configuration and conformation of two diastereoisomeric fukinone epoxides were unambiguously established by NMR (NOESY), CD, and X-ray crystallographic analyses of their derivatives. The data show the absolute configurations of exo α,β-epoxy ketones can be predicted by an octant rule, not by a Reverse Octant Rule.
Published online: 2nd November, 2010
■ Asymmetric Intramolecular Aldol Reaction Mediated by (S)-N-Substituted-N-(2-pyrrolidinylmethyl)amine to Prepare Wieland-Miescher Ketone
Yuichi Akahane, Kohei Inomata,* and Yasuyuki Endo
*Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
Abstract
New or known N-substituted-N-(2-pyrrolidinylmethyl)amine deriva- tives bearing a variety of alkyl and aryl substituents were easily prepared from N-Boc-proline or N’-Boc-N-(2-pyrrolidinylmethyl)amine. The enantioselectivity of the intramolecular asymmetric aldol reaction mediated by a combination of the amine derivative and TFA to prepare Wieland-Miescher ketone was examined. During the examination, optimal amount of TFA in the reaction was identified.
Published online: 20th January, 2011
■ Oxidative Coupling of Indoles with 3-Oxindoles
Mikkel Jessing and Phil S. Baran*
*Department of Chemistry, The Scripps Research Institute, 10550 N. Torrey Pines Road,
BCC-169, La Jolla, CA 92037, U.S.A.
Abstract
A mild procedure for the union of 3-oxindoles with indoles is reported using oxidative coupling.