Deamination alcohol synthesis

Notable examples of general synthetic procedures in Volume 47 include the synthesis of aromatic aldehydes (from dichloro-methyl methyl ether), aliphatic aldehydes (from alkyl halides and trimethylamine oxide and by oxidation of alcohols using dimethyl sulfoxide, dicyclohexylcarbodiimide, and pyridinum trifluoro-acetate the latter method is particularly useful since the conditions are so mild), carbethoxycycloalkanones (from sodium hydride, diethyl carbonate, and the cycloalkanone), m-dialkylbenzenes (from the />-isomer by isomerization with hydrogen fluoride and boron trifluoride), and the deamination of amines (by conversion to the nitrosoamide and thermolysis to the ester). Other general methods are represented by the synthesis of 1 J-difluoroolefins (from sodium chlorodifluoroacetate, triphenyl phosphine, and an aldehyde or ketone), the nitration of aromatic rings (with ni-tronium tetrafluoroborate), the reductive methylation of aromatic nitro compounds (with formaldehyde and hydrogen), the synthesis of dialkyl ketones (from carboxylic acids and iron powder), and the preparation of 1-substituted cyclopropanols (from the condensation of a 1,3-dichloro-2-propanol derivative and ethyl-... 

Process development of the synthesis of iodoaniline 28 began with an improved synthesis of l-(4 -aminobenzyl)-l,2,4-triazole (6) (Scheme 4.7), which was prepared in the medicinal chemistry synthesis, albeit with poor regioselectivity (Scheme 4.1). We found that this aniline intermediate 6 could be readily prepared in three steps in >90% overall yield from 4-amino-l,2,4-triazole (30) and 4-nitrobenzyl bromide (4) based on a modified literature procedure [9]. The condensation of 30 and 4 in isopropyl alcohol followed by deamination gave the nitro... 

As VAO is able to perform an oxidative deamination of capsaicin-derived vanillyl amine, vanillin can be produced by the pathway described in the previous subsection. Van den Heuvel et al. [83] pointed out this biocatalytic route of synthesis in 2001 using penicillin G acylase to obtain vanillyl alcohol from natural capsaicin (Scheme 22.6). As the vanillin obtained can be labelled as natural. 

The catalytic hydrogenation of nitro alcohol to amino alcohol has been applied to the synthesis of an intermediate leading to sugar alcohols. The condensation of ni-tromethane with pentoses in the presence of sodium methoxide, followed by hydrogenation over platinum oxide and deamination with nitric acid, gave the alditols with one more carbon atom.22 The reaction sequence is as follows pentose — 2-epimeric sodio aci-nitro alcohols —> 2-epimeric hexitylamines —> 2-epimeric hexitols + 2-epi-meric 1,4-anhydrohexitols. The 2-epimeric sodio a -nitro alcohols were hydrogenated to 2-epimeric hexitylamines over platinum oxide in acetic acid. An example is shown in eq. 9.8 with D-ribose. 

We described an unusual oligomer whereby a-amino acids were converted into a-hydroxy acids by oxidative deamination with retention of stereochemistry, followed by reduction to 1,2-diols. The primary alcohol was protected by the dimethoxytrityl group, and the remaining secondary alcohol converted to a phos-phitylating agent. These monomers could then be incorporated into oligomers under the standard conditions of automated DNA synthesis. The resulting molecules retain amino acid side-chains, but have the phosphodiester backbone more familiar to nucleic acids. 

Cyclobutanol was obtained by deamination of (cyclopropylmethyl)amine in 40% yield. Cyclopropylmethanol was a major byproduct in this reaction. A more efficient synthesis of cyclobutanol is the acid-catalyzed rearrangement of cyclopropylmethanol with aqueous hydrochloric acid " cyclobutanol was obtained in 72% yield containing a trace of the allyl alcohol. This transformation forms the basis of an efficient cyclobutene synthesis. ... 

The deamination of phosphoramidates by isoamyl nitrite has been mentioned in previous Reports and is the basis of a method for the protection of 5 -phosphoryl groups in the synthesis of oligonucleotides. The oxidation of nucleoside phosphoramidates with bromine in the presence of alcohols leads to phosphodiesters. The AT-bromophosphoramidate which is presumably an intermediate should break down by a pathway which is similar to that of the acid-catalysed decomposition of phosphoramidates. 

Hydroxytryptamine is deaminated oxidatively to 5-hydroxyindole acetic acid. In addition, 5-hydroxytryptamine is catabolized in substantially smaller amounts by reduction to the corresponding alcohol, 5-hydroxytryptophol, (1868-70) is excreted in the free form and combined as the glucuronide or sulphate. 7V-Methylation of 5-hydroxytryptamine gives iV-methylsero-tonin, which can be methylated further to 7V, -dimethylserotonin (= bufotenine). The iV-methylation is catalysed by a relatively unspecific iV-methyltransferase. By acetylation of 5-hydroxytryptamine 7V-acetyl-serotonin is produced, which is an intermediary product in the course of the melatonin synthesis (= 5-methoxy-AT-acetylserotonin). The production of 5-methoxytryptamine, which we were able to demonstrate in normal human blood and urine, seems to occur fairly easily by deacetylation of melatonin, whereas a direct 0-methylation of serotonin to 5-methoxy-tryptamine, at least in vitro, takes place to a substantially smaller extent. ... 

Nonoxidatioe. A single enzyme which catalyzes the deamination of L-serine and the synthesis of cystathionine has been partially purified from rat liver (496). A camino acid dehydrogena.se, distinct from alcohol dehydrogenase, has been obtained from N. crassa (497). 

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