3- Methylbut-3-enoyl chloride

Indol-l-ylzinc chloride 3-Methylbut-2-enoyl chloride 70 [1]... 

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. 

Generally, the products formed by the catalytic decarbony-lations of acid halides are easily predicted. Some of the few instances where this is not the case are the decarbonylations of pent-3-enoyl or 2-methylbut-3-enoyl chlorides. Here the formation of ry - y complexes after decarbonylation results in several products being formed. ... 

Analysis of Tagetes minuta. L. (Compositae) revealed the presence of cis- (40a) and trans- (40b) -ocimenones (= tagetenones), in addition to the previously known tagetones and dihydrotagetones. The new compounds were synthesized by treatment of a mixture of 3-methylbut-2-enoyl chloride and isoprene with a Lewis acid, e.g. SbClg. ... 

The efficient addition of allylic bromides to carbonyl compounds in a heated zinc column has been used to synthesize ( )-artemisia alcohol (81 R = H, X = CH2) in 91% yield.Artemisia ketone was synthesized efficiently from 3-methyl-l-trimethylsilylbut-2-ene and 3-methylbut-2-enoyl chloride in the presence of AlCls. Racemic methyl santolinate (82) was synthesized (along with the C-3 epimer ratio 8 1) via Claisen rearrangement, according to Scheme 2 (cf. Vol. 6, p. 7). ... 

More recently, Rousseau and Blanco reacted 3-methylbut-2-enoyl chloride with a number of silyl ketene acetals to produce -Yid-ethylenic P-keto esters, with yields in the range 62-80% neither but-2-enoyl chloride nor propenoyl chloride reacted under these conditions. They employed this reaction in a new synthesis of ( )-turmerone (6 Scheme 12). 

Draw (a) 2,3-diphenylhex-2Z-enoic acid, (b) 3-methylbut-2-enoyl chloride, and (c) methyl 4-phenylbut-2E-enoate. 

Anisole and many of its derivatives react with an unsaturated acid chloride in the presence of aluminum chloride to yield a chromanone (20LA(42l)l). The two most widely used acid halides are but-2-enoyl (crotonyl) and 3-methylbut-2-enoyl (3,3-dimethylacryloyl) chlorides. In cases where the uncyclized intermediate, an acrylophenone, is isolated, cyclization may be achieved under acidic or basic conditions, or even simply by distillation (Scheme 220) (52G155). 

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