Syntheses of l-Sorbosylthymines and Related Compounds

Abstract

1, 3, 4, 5-Tetra-O-acetylsorbopyranosylureas were prepared from sorbopyranosyl chloride via 1, 3, 4, 5-tetra-O-acetylsorbopyranosylisocyanates. 1-Ureido- and 6-ureidosorbofuranoses were obtained from the corresponding aminosorboses. The transformations of the ureas thus obtained into N-(sorbose)thymines were achieved, although with difficulty, by the direct condensation of halogeno- or tosylsorboses with metal salts of thymine.

The Acetalation Mechanism of l-Sorbose

“…1-OMethyl-L-sorbose (X)24) was prepared from 1-Ofuranose (XI)25) by partial deacetonation with 60% acetic acid to give 1-O-methyl-2,3-Oisopropylidene-a-L-sorbofuranose (XII), 25) followed by further deacetonation with 1 N hydrochloric acid. at room temperature.…”

CVD Hydrophobic Lead Silicate Films

“…Chemically deposited silica film, whether prepared from simple silane or tetraethylorthosilicate (TEOS), generally exhibits hydrophilic property, which is highly undesirable in microelectronic applications, as the moisture absorbed by the film in certain instances can adversely deteriorate a device's stability. Others have suggested several hydrophobization methods, including the surface treatment (1-3) with some selected compounds to provide a nonpolar surface, or an overlay coating of some hydrophobic oxide (4) or nitride as a protective barrier. But these methods are generally ineffective in microelectronic encapsulation, and they cannot provide a permanent hydrophobization that can survive through a series of device manufacturing steps.…”