Steroid sugars

The ImCSIm-method has been used, for instance, in the synthesis of isothiocyanates containing steroid, sugar, and alkaloid components ... 

Alcohols, drugs, herbicides, pesticides, phenols, steroids, sugars... 

When intermediate 274 reacted with ketones 133 (from D-glucose) or 270 (from D-fructose), mixed steroid-sugar compounds 278 and 279 were, respectively, obtained in low yields (10-16%). In addition, the use of protected estrone 280 (precursor of the epoxide 272) as electrophile allows the preparation of the dimeric steroid 281 in 26% yield. The low yields obtained for compounds 278, 279 and 281 are due to extensive decomposition during their column chromatographic purification. 

The chemistry of those oxepanes which may be classified as terpenes, steroids, sugars and alkaloids has been covered in depth elsewhere (72HC(26)l) and thus will not be included in the present chapter. 

The reaction of many compounds of biological interest with ammonium bicarbonate on thin-layer plates permits detection of 10-100-ng amounts of these compounds [141]. Many compounds in the lipid, steroid, sugar, amino acid, purine, pyrimidine and alkaloid classes can be analyzed in this way (Table 4.26). 

Generally useful reagent with a high silyl donor ability will not react with amino groups will not cause formation of enol-ether on unprotected ketone groups especially useful for ecdysones, norepinephrine, dopamine, steroids, sugars, sugar phosphates, and ketose isomers... 

Refluxing or photolytic treatment of O-acyl esters (2) in the presence of a hydrogen donor such as Bu3SnH or ter -BuSH, provides the corresponding reduction products via alkyl radicals. This reaction can be applied to primary-, secondary-, and tertiary-alkyl chained carboxylic acids, and can also be used for steroids, sugars, and peptides as shown in eq. 8.4 [9-14]. Racemization does not occur at other chiral centers. 

This review of literature covering phytochemical investigations on ten Taxus species have resulted in the isolation of nearly three hundred and fifty compounds belonging to the classes of taxanes, lignans, flavonoids, steroids, sugar derivatives, aromatic acids, etc. 

Hundreds of applications have been mentioned in the Zweig (1968) review acids, alkaloids, amino acids, antibiotics, antioxidants, food and feed additives, bases and amines, bile acids, carbonyls, dyes, enzymes, lipids, hydrocarbons, hormones, indoles, natural products, peptides, proteins, pesticides, plant growth regulators, pharmaceutical products, phenols, pigments (chlorophylls, xanthophylls, porphyrins, melanin, pterins, pteridines, anthocyanins, ilavonoids, etc.), polymers, purine and pyrimidine derivatives, quinones, RNA, DNA, organic sulfur compounds, steroids, sugars, toxins, vitamins, inorganic ions, and others. 

Natural products (steroids, sugars, alkaloids, prostaglandins, etc.) usually have conventional, though arbitrary, layouts and orientations. 

A major trend in organic synthesis, however, is the move towards complex systems. It may happen that one needs to combine a steroid and a sugar molecule, a porphyrin and a carotenoid, a penicillin and a peptide. Also the specialists in a field have developed reactions and concepts that may, with or without modifications, be applied in other fields. If one needs to protect an amino group in a steroid, it is advisable not only to search the steroid literature but also to look into publications on peptide synthesis. In the synthesis of corrin chromophores with chiral centres, special knowledge of steroid, porphyrin, and alkaloid chemistry has been very helpful (R.B. Woodward, 1967 A. Eschenmoser, 1970). 

The diphenylmaleimide is prepared from the anhydride, 33-87 % yield, and cleaved by hydrazinolysis, 65-75% yield. It is stable to acid (HBr, AcOH, 48 h) and to mercuric cyanide. It is colored and easily located during chromatography, and has been prepared to protect steroidal amines and amino sugars. " ... 

Fatty acids, triglycerides, amino acids, sugars, steroids [1] CH3... 

When used at room temperature in the presence of an active platinum catalyst in an inert solvent, e.g., acetone or ethyl acetate, oxygen will oxidize nonhindered, saturated hydroxyl groups and exposed allylic alcohols. This reagent has found extensive use in sugar chemistry and is particularly suited for the selective oxidation of either 3a- or 3j -alcohols of steroids. Other hydroxyl groups on the steroid skeleton are much less sensitive to oxidation. As a result, this reaction has been used extensively in research on polyhydroxy cardiac-active principles, e.g., the cardenolides and bufadienolides, where the 3-hydroxyl group is easily oxidized without extensive oxidation or dehydration of other hydroxyl groups. The ordinarily difficult selective oxidation of the... 

Disulfonate esters of vicinal diols sometimes undergo reductive elimination on treatment with sodium iodide in acetone at elevated temperature and pressure (usually l(X)-200°). This reaction derived from sugar chemistry has been used occasionally with steroids, principally in the elimination of 2,3-dihy-droxysapogenin mesylates. The stereochemistry of the substituents and ring junction is important, as illustrated in the formation of the A -olefins (133) and (134). 

Steroids, e.g. cholesterol, triolein, androsterone sugars, e.g. fructose, glucose, ribose amino acids, pyrimidines, purines, alkaloids 110-150°C, 2-12 h Conversion to fluorescent derivatives by heating. [5]... 

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