Tigloyl chloride

Tigloyl chloride.190 (E)-2-methylbut-2-enoyl chloride. ]. Tiglic acid (20 g) and phosphorus trichloride (15 g) are heated together at 70-80 °C for 2 hours. The upper, slightly yellow, layer is decanted from the lower syrupy layer and distilled at 64°C/35mmHg to give the acid chloride in 90 per cent yield. 

The synthesis of 5,7-dimethoxy coumarin 39 started from phloroglucinol through coumarin construction by Pechman reaction followed by methylation via two steps. The resulting 8-tigloylated coumarin 40 (Scheme 8-9) was obtained by treatment of the coumarin (39) with tigloyl chloride according to the preparation method described in Scheme 8-8. 

Tiglic acid, 421, 423 Tigloyl chloride, 365 Titanium(O), 481-482, 483 Titanium(lII) chloride, 482-483 Titanium(l 11) chloride-Zinc/copper couple, 483... 

Motoyoshiya et al. in the course of their studies on the Nazarov reaction [19] found a convenient method for the synthesis of 1, whose substituted cyclopen-tenone ring with the exocyclic a-methylene group was constructed in one operation [20]. This synthesis began with the acylation of dimethyl methanephos-phonate 9 with tigloyl chloride to produce the unsaturated jS-ketophosphonate 10 which in the next step was reacted with aqueous formaldehyde to give the dienone 11. The Nazarov reaction of the latter provided methylenomycin B (1) in 12% overall yield (Scheme 5). 

A mixture of 2,4-dimethylresorcinol dimethyl ether and tigloyl chloride added with vigorous stirring at 60-70° to polyphosphoric acid, heated to 110°, kept 5 min. at this temp., then poured into ice-water 2,3,4,6-tetramethyl-5,7-di-methoxyindanone (Y 89%) stirred 3 hrs. at room temp, with LiAlH4 in dry ether 2,3,4,6-tetramethyl-5,7-dimethoxyindanol (Y ca. 100%) dissolved in benzene containing p-toluenesulfonic acid, and refluxed with azetropic water... 

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