Galactal

In the x-ray portion of the spectmm, scientific CCDs have been utilized as imaging spectrometers for astronomical mapping of the sun (45), galactic diffuse x-ray background (46), and other x-ray sources. Additionally, scientific CCDs designed for x-ray detection are also used in the fields of x-ray diffraction, materials analysis, medicine, and dentistry. CCD focal planes designed for infrared photon detection have also been demonstrated in InSb (47) and HgCdTe (48) but are not available commercially. 

The longest wavelengths of the electromagnetic spectmm are sensitive probes of molecular rotation and hyperfine stmcture. An important appHcation is radio astronomy (23—26), which uses both radio and microwaves for chemical analysis on galactic and extragalactic scales. Herein the terrestrial uses of microwave spectroscopy are emphasized (27—29). 

G. L. Verschuur and K. I. KeUermann, eds.. Galactic and Extragalactic Radio Astronomy, 2nd ed., Springer-Vedag, New York, 1988. 

Ieje93] Lejeune, A., CA simulations of galactic stellar distributions, pages 323-341 in [perd93aj. 

Subsequently this route to 3-deoxy sugars was developed by further work in our laboratory by Ferrier and Sankey (23). They demonstrated that although tetra-O-acetyl-2-hydroxy-D-galactal undergoes rearrangement in boiling acetic acid, and that reaction is speeded up and goes to completion if catalytic amounts of methanesulfonic acid are added, the... 

From the rearrangement of tetra-O-acetyl-2-hydroxy-D-galactal in boiling acetic acid it was possible to isolate l,2,4,6-tetra-0-acetyl-2,3-dide-h.ydro-3-deoxy-a-jy-threo-hexose (32) (58%) and a small amount of 1,2,3,4,6-penta-O-acetyl-jS-D-galactopyranose. In the reaction mixture the presence of some a-pentaacetate was demonstrated chromatographically but NMR spectroscopy indicated no resonances corresponding to the / anomer of compound 32. These spectral measurements indicate that compound 32 constituted 80% of the mixture of products. 

Two further examples of similar types of analyses using the RI detector is afforded by the separation of the products of P-cyclodextrin hydrolysis and of the partial hydrolysis of galaction. 

The separation of the hydrolysates of galaction affords a further example of the use of the RI detector for organic polymers. The... 

Figure 3. Sky coverage of an adaptive optics at an 8m telescope. Pupil sampling by the actuators of the deformable mirror 0,5m, 0 = 0,17m, From top to bottom in a direction of galactic latitude 6 = Of (the Milky Way), b = 20f and b = 90f (the galactic pole). From left to right K, 1 and V bands.

With a single deformable mirror AO, and if a single NGS is used (see Le Louam and Hubin, 2004), the point spread function is quite peaked in the corrected field, but the probability to find if is much higher from fa 10 toward the galactic pole for observations in the visible to 50% toward the galactic plane for observations in the near infrared. 

MCAO without LGSs is limited to the infrared domain, with a better probability close to the Galactic plane... 

Deoxy-2-[ F]fluoro-D-galactose can be prepared through an addition reaction to tri-O-acetyl-D-galactal (465), but better through Sn2 reaction (K F-Kryptofix 222 in MeCN) of methyl 3,4-0-isopropylidene-2-0-triflyl-6-0-trityl-y -D-talopyranoside (220 see Section 11,2), according to the cold synthesis. 

D-/yAc>-hexoside from D-galactal, a reaction which defines the stereospecificity of glycosyl transfer to the acceptor oxygen atom. 

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