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
Ekkehard Winterfeldt's Special Issues, Vol. 74, No. 1, 2007
Published online: 28th September, 2007
■ New Sesquiterpenoids from Curcuma aff. aeruginosa Roxb.
Phan Minh Giang, Phan Tong Son, Katsuyoshi Matsunami, and Hideaki Otsuka*
*Divison of Medicinal Chemisry, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
Abstract
Two new natural sesquiterpenoids, designated aeruginolactone (3) and aeruginone (10), and eight known sesquiterpenoids were isolated from the rhizomes of Curcuma aff. aeruginosa Roxb. (Zingiberaceae). Their structures were determined using spectroscopic analyses.
Published online: 23rd October, 2007
■ An Efficient, One-Pot Synthesis of Fosfomycin Dialkyl Esters from (R)-2-Tosyloxypropanal
Tadashi Hanaya,* Yuichi Nakamura, and Hiroshi Yamamoto
*Faculty of Science, Okayama University, 3-1-1 Tsushima-naka, Okayama 700-8530, Japan
Abstract
(R)-2-Tosyloxypropanal (4) was prepared from D-mannitol in a 7-step sequence (51% overall yield). Addition of dialkyl phosphonates to 4 in the presence of titanium isopropoxide and the subsequent treatment with DBU stereoselectively afforded, in one-pot, fosfomycin dimethyl (5a) and dibenzyl (5b) esters both in 58% isolated yield.
Published online: 23rd October, 2007
■ Production of Large-Ring Cyclodextrins Composed of 9 ~ 21 α-D-Glucopyranose Units by Cyclodextrin Glucanotransferase — Effects of Incubation Temperature and Molecular Weight of Amylose
Tomohiro Endo,* Noriko Ogawa, Hiromasa Nagase, Haruyo Sambe, Takeshi Takaha, Yoshinobu Terada, Wolfgang Zimmermann, and Haruhisa Ueda
*Department of Physical Chemistry, Hoshi University
2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
Abstract
Cyclodextrin glucanotransferase (CGTase) is the only enzyme that can produce large-ring cyclodextrins (LR-CDs) composed of 9 ~ 21 α-D-glucopyranose units (CD9 ~ CD21). In this study, two amyloses with different average molecular weights (14.6 and 280 kDa) were incubated with CGTase at three different temperatures, and the yield and composition of the LR-CDs were examined. The composition was not significantly affected by the size of amylose used, but was greatly affected by the reaction temperature.
Published online: 2nd November, 2007
■ Synthesis of a Cyclic Guanidine Hemiaminal Pertinent to the Axinellamines
Liang Tang and Daniel Romo*
*Department of Chemistry, Texas A & M University, College Station, Texas 77843-3255, U.S.A.
Abstract
Potential methods for the generation of the cyclic guanidine hemiaminal functionality of axinellamine A (1) from a hydantoin precursor are examined. An activation-reduction sequence was developed for the reduction of cyclic acyl guanidines.
Published online: 16th October, 2007
■ Preparation of 2-Dialkylamino-1,3-selenazoles by Reaction of N,N-Unsubstituted Selenoureas with α-Diketones
Koichi Kanoh, Hideharu Ishihara, and Mamoru Koketsu*
*Department of Chemistry, Faculty of Engineering, Gifu University, 1-1 Yanagito, Gifu, Gifu 501-1193, Japan
Abstract
2-Dialkylamino-1,3-selenazoles were obtained by the reactions of N,N-unsubstituted selenoureas with ±-diketone derivatives in alcohol in the presence of ferric chloride at room temperature.
Published online: 9th November, 2007
■ Heterocycles from Ylides. Part XI. Synthesis of 2-Substituted Quinoline Derivatives
Giuseppe Cremonesi, Piero Dalla Croce,* Francesco Fontana, and Concetta La Rosa
*Department of Organic and Industrial Chemistry, C.N.R. - I.S.T.M., University of Milano, Via Venezian 21, I-20133 Milano, Italy
Abstract
The reaction of 2-N-phenylsulfonylaminobenzaldehyde (1) with stabilized alkylidene phosphoranes (2) gives, through a Wittig condensation followed by reduction of intermediate alkenes and cyclization with PPA, quinoline derivatives (5).
Published online: 22nd November, 2007
■ X-Ray Crystal Structure of Dibenzo[a,d]cycl[2.2.3]azines
Kiyoshi Matsumoto,* Hirokazu Iida, Seisuke Mimori, Hiroshi Hamana, Takane Uchida, and Akikazu Kakehi
*Faculty of Pharmaceutical Sciences, Chiba Institute of Science, 3 Shiomi-cho, Choshi, Chiba 288-0025, Japan
Abstract
The results of X-ray analyses of a novel type of heterocycles, 2-benzoyl- and 1,3-dimethyldibenzo[a,d]cycl[2.2.3]azines were described, which offer further evidence for the 18π peripheral conjugate nature of dibenzo[a,d]cycl[2.2.3]azines. The molecules are essentially planer as is the parent cycl[2.2.3]azine, but less strained.