Hexopyranoses

Hexamine — see Hexamethylenetetramine 1,4,7,10,13,16-Hexaoxacyclooctadecane — see [18]Crown-6 Hexazinone as herbicide, 1, 187 Hex-2-enopyranoside, 2,3-dideoxy-synthesis, 1, 464 Hexobarbital, 3, 150 Hexogen, 3, 530 a-D-galacto- Hexopyranose nomenclature, 1, 31 Qf-D-ido-Hexopyranose nomenclature, 1, 31... 

This is the first case to observe 2,4-diamino-2,3,4,6-tetradeoxy-D-arafoino-hexopyranose in natural products and the first isolation of d-inositol from microbial products. Kasugamycin is the first compound possessing a unique group of an amidine carboxylic acid. 

All derivatives used were prepared by essentially standard literature procedures and had physical constants in accord with previously reported values. Furthermore, the P.M.R. spectra were in each case consistent with the assigned structures. All solutions were concentrated under reduced pressure and m.p. s are uncorrected. (I) 2-Deoxy-D-arafczno-hexopyranose was a commercial sample from Pfanstiehl Lab. Inc., Waukegan, Illinois and was used without further purification. (II) 3, 4, 6-Tri-O-acetyl-D-glucal (1) was a commercial sample from Aldrich Chem. Co., Milwaukee, Wisconsin and was purified by distillation and recrystallized three times from aqueous ethanol. (Ill) 1, 3, 4, 6-tetra-0-acetyl-2-deoxy-a-D-arahino-hexopyranose (4) was prepared by the method of Bonner (11) while the corresponding / -anomer (5) was synthesized following the procedure of Overend, Stacey, and Stanek (47). (IV) 5, 6-Dideoxy-1, 2-0-isopropylidene-a-D-xj/io-hex-5-enofuranose (20) was provided by A. Rosenthal and G. Khan of this Department. 

For reasons which will be discussed later, we were interested in obtaining a detailed analysis of the P.M.R. spectrum of both the a-(2) and j8-(3) anomers of 2-deoxy-D-arahmo-hexopyranose in D20 solution. 

The P.M.R. spectrum of an equilibrated aqueous solution of 2-deoxy-D-arafoino-hexopyranose was first measured by Lenz and Heeschen (37) who reported values for the chemical shifts of the anomeric protons and... 

Figure 3. 100 MHz P.M.R. Spectrum of an equilibrated solution of 2-deoxy-v-snabino-hexopyranose in DtO.

Figure 4. Partial 100 MHz P.M.R. spectra of an equilibrated solution of 2-deoxy-B-siYabmo-hexopyranose in D2O solution (B) normal resonance (A) with irradiation of Ht(a) (C) with irradiation of Hi(fl).

The study of Lemieux and co-workers (38, 39) which first delineated the stereospecific dependences of the P.M.R. parameters of pyranose derivatives has since been confirmed by many workers (24, 40, 44). In the following section we shall discuss some of the more recently recognized stereospecific dependences, dealing first with the dependences of coupling constants and then with those of chemical shifts. Reference will be made to the P.M.R. parameters of the hexopyranose derivatives which were obtained in experiments outlined in the previous section, together with the parameters of the a-(4) and, / -(5) anomers of 1, 3, 4, 6-tetra-0-acetyl-2-deoxy-D-arafoino-hexopyranose. 

One of the most interesting stereospecific dependences which followed from the original study (38,39) of O-acetylated hexopyranose and pento-pyranose derivatives was that of the anomeric proton shifts. In general it was found that the axially oriented anomeric protons gave resonances to higher field than the equatorially oriented protons. Many subsequent studies of pyranose derivatives (24,40) and of inositol derivatives (43)... 

Deoxyhex-5-enose derivatives. 120 2-Deoxy-D-arabino-hexopyranose,... 

Deoxy-p-D-xy/o-hexopyranose 2-Deoxy-D-ribo-hexose not 2-deoxy-D-allose not 4-deoxy-p-D-galactopyranose... 

Deoxy-2-phenyl-a-D-glucopyranose or 2-deoxy-2-C-phenyl-a-D-glucopyranose or (2fl)-2-deoxy-2-phenyl-a-D-arab/no-hexopyranose... 

Trideoxy-3-C-methyl-4-Omethyl-3-nitro-L-arab/no-hexopyranose... 

Trideoxy-3-C-methyl-4-0-methyl-3-nitro-D-/yxo-hexopyranose (nitrogen has priority over carbon for determining configuration)... 

Methyl p-D-talopyranose-2-C,4-C-diylphosphinite or 2-C,4-C-fmethoxyphosphanediyl)-p-D-glucopyranose or (2fl,4S)-2-C,4-C-(methoxyphosphanediyl)-P-D-/hreo-hexopyranose... 

Note 1. The alternative name using a substituent prefix (see 2-Carb-35.1) is 4-0-acetyl-3-amino-2,3,6-trideoxy-l-0,3-N-(ethan-l-yl-l-ylidene)-3-C-methyl-a-L-rifco-hexopyranose... 

Fully acetylated hexopyranoses react with thiols in the presence of Lewis acids, such as BF3-Et20.32,33 The reaction is faster with 1,2-trans acetates than with the corresponding 1,2-cij ones and 1,2-trans products predominate. Alkyl, alkenyl, and aryl thioglycosides are produced by this method. Variations on this method include the use of trimethylsilyl34 or stannyl derivatives35 of the thiols. 

There are two forms of carba-sugar carba-pyranoses and -furanoses. The former, especially the carba-hexopyranoses, have been extensively studied during the past two decades, ever since their derivatives were found in Nature as components of important antibiotics. However, very little is known about carba-furanoses, except for 4a-carba-)3-L-arabinofuranose ... 

This article, therefore, focuses on the chemistry of carba-hexopyranoses and their derivatives, in which accomplishments are most evident. 

Physiol Properties of Amino Carba-hexopyranose Penta-A/, O- Acetates... 

Enzyme and source 5-Amino-S-deoxy- hexopyranose 1,5-Dideoxy- 1,5-iminohexitol Glycosylamine References... 

Stereospecific dependencies of the nonselective relaxation-rates for other protons in a sugar molecule may be seen in the data for a set of 3,4,6-tri-O-acetyl-l-0-benzoyl-2-deoxy-2-bromo-D-hexopyranose derivatives (40-42), as well as other 2-halogeno derivatives. A comparison of their... 

Qualitative relaxation-studies have also been reported for an extensive series of derivatives of inositols, pentopyranoses, l,6-anhydro-/3-D-hexopyranoses, furanoses, and septanoses. In all instances, the experimentally determined Ri(ns) values reflect the anticipated geometry. For the furanose derivatives especially, they provide a better means for distinguishing between epimeric pairs than the relatively ambiguous interpretation of coupling-constant data. 

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