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Acetyl phloroglucinol

The C-methyl group attached to the ring in typical phenols (formed by an aldol condensation step), such as 6-methylsalicyclic acid (I), orsellinic acid (V), and altemariol (III), is derived from the acetyl-CoA primer. In other representative compounds, for example acetyl phloroglucinol (VI), an acetyl residue remains external to the ring as a result of cyclization by a C-acyla-tion process (Birch and Donovan, 1953). [Pg.540]

Phloroglucinol (25) is more susceptible to oxidation than both phenol and resorcinol. However, its direct nitration to 2,4,6-trinitrophloroglucinol (27) can be achieved by the slow addition of a nitrating agent composed of concentrated sulfuric acid and concentrated nitric acid to a solution of phloroglucinol dihydrate in concentrated sulfuric acid between 0 and 10 °C (72 Acetylation of phloroglucinol (25) yields the triacetate (26) which moderates... [Pg.133]

An amorphous preparation was made similarly from 2,3,4,6-tetra-O-acetyl-(2-hydroxy-D-galactal).9 It was noted that this preparation did not give the reactions reported by Helferich for the 5,6-anhydro derivative with pyrogallol, orcinol, aniline, and m-nitroaniline. However, it did give a voluminous, red-brown precipitate with phloroglucinol. [Pg.124]

The Hoesch reaction is the most satisfactory method for preparing phloroacetophenone.3 The procedure described above is that of Robinson and Venkataraman.4 Phloroacetophenone has been obtained also by the action of acetyl chloride on phloroglucinol in the presence of aluminum chloride.2... [Pg.71]

Acetoxy-3,5-dimethoxyphenyl)-5,7-diacetyl-3-acetoxyflav-3-ene has been synthesised from the quinonemethide shown by addition to a benzene/dimethyl formamide (25 1) solution of phloroglucinol followed by reaction for 2 mins, in the presence of a catalytic quantity of 4-toiuenesulphonic acid to give initially the open chain C-alkylated intermediate in 48% yield. This was stirred for 48 hours at ambient temperature in benzene/acetone containing silver oxide and was then acetylated with acetic anhydride/pyridine (ref. 10). [Pg.341]

Treatment of methyl 2,3,4-tri-0-acetyl-6-deoxy-6-iodo-a-D-glucopyranoside with sodium nitrite and phloroglucinol gave the 6-deoxy-6-nitro-sugar, which was converted, via the a-bromide, into the corresponding adenin-9-yl nucleoside. ... [Pg.74]

Also obtained (major product) by reaction of acetyl chloride on phloroglucinol trimethyl ether with aluminium chloride in boiling petroleum ether [3086],... [Pg.838]

Preparation by reaction of acetyl chloride with 2,4-diethyl-phloroglucinol in the presence of aluminium chloride in nitrobenzene (28%) [3401],... [Pg.929]

Also obtained (by-product) by Friedel-Crafts acylation of phloroglucinol trimethyl ether with acetyl chloride in the presence of aluminium chloride in boiling carbon disulfide [5819]. N.B. No direct proof of the constitution of the diketone was described, bnt it wonld appear most probable that it is 3-acetyl-6-hydroxy-2,4-dimethoxyacetophenone [5819]. [Pg.1581]

The synthesis of phenols via the acetate-malonate pathway shows similarities to the synthesis of the fatty acids. In the case of the latter acetyl CoA was the initiator, and here various other acyl CoAs serve this purpose. Three units of malonyl CoA are added to the initiator with accompanying decarboxylation. We may remember that in the case of the fatty acids malonyl CoA was also added with decarboxylation until the final chain length was obtained. In the present case, a polyketoacid is formed which can cyclize in different ways. We are interested here only in the so-called 1-6 C acylation which gives rise to the phenols with the hydroxyl pattern of phloroglucinol. They differ in the nature of their R substituent and, in addition, can be subjected to further modifications. [Pg.120]

Fucols. These are simple oligomers of phloroglucinol coming only from C—C couplings (the gray circles represent hydroxy or acetyl groups). [Pg.443]


See other pages where Acetyl phloroglucinol is mentioned: [Pg.896]    [Pg.344]    [Pg.896]    [Pg.344]    [Pg.383]    [Pg.449]    [Pg.248]    [Pg.383]    [Pg.1007]    [Pg.1007]    [Pg.198]    [Pg.2315]    [Pg.430]    [Pg.110]    [Pg.18]    [Pg.614]    [Pg.322]    [Pg.2314]    [Pg.287]    [Pg.530]    [Pg.722]    [Pg.837]    [Pg.1559]    [Pg.468]    [Pg.5]   
See also in sourсe #XX -- [ Pg.540 ]

See also in sourсe #XX -- [ Pg.126 ]




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Phloroglucinols

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