Special Issue

Ekkehard Winterfeldt's Special Issues, Vol. 74, No. 1, 2007

97 data found. 91 - 97 listedFirst Previous
Note | Special issue | Vol 74, No. 1, 2007, pp. 977 - 981
Published online: 28th September, 2007
DOI: 10.3987/COM-07-S(W)42
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.

PDF (271KB)
Note | Special issue | Vol 74, No. 1, 2007, pp. 983 - 989
Published online: 23rd October, 2007
DOI: 10.3987/COM-07-S(W)45
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.

PDF (428KB)
Note | Special issue | Vol 74, No. 1, 2007, pp. 991 - 997
Published online: 23rd October, 2007
DOI: 10.3987/COM-07-S(W)64
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.

PDF (369KB)
Note | Special issue | Vol 74, No. 1, 2007, pp. 999 - 1008
Published online: 2nd November, 2007
DOI: 10.3987/COM-07-S(W)66
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.

PDF (255KB)
Note | Special issue | Vol 74, No. 1, 2007, pp. 1009 - 1014
Published online: 16th October, 2007
DOI: 10.3987/COM-07-S(W)71
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.

PDF (169KB)
Note | Special issue | Vol 74, No. 1, 2007, pp. 1015 - 1018
Published online: 9th November, 2007
DOI: 10.3987/COM-07-S(W)78
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).

PDF (169KB)
Note | Special issue | Vol 74, No. 1, 2007, pp. 1019 - 1025
Published online: 22nd November, 2007
DOI: 10.3987/COM-07-S(W)85
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.

PDF (448KB)
97 data found. 91 - 97 listedFirst Previous