Senecioyl chloride

A mixture of senecioyl chloride (0.1 mol) and A1C13 (0.1 mol) in dichloromethane (50 ml) was added dropwise over 45 min with stirring to a solution of dimethylallyltrimethylsilane (O.llmol) in dichloromethane (KK)ml), previously cooled to — 60 °C. The reaction mixture was maintained at this temperature for 10 min after the final addition, and then poured slowly onto a mixture of crushed ice and ammonium chloride. After washing of the organic layer with brine and drying, artemisia ketone (0.09 mol, 90%). b.p. 87°C/200mmHg, was obtained. 

SN displacement reactions, 27-9 a-Selenocyclohexanones, 77 Senecioyl chloride, 33 Silmagnesiation, platinum-catalysed, 8 Silametallation of terminal alkynes, 7-9 Silver acetylide, 49 Silver trifluoroacctate, 42,127 Silyl cuprates, 7... 

As part of a general investigation of terpenoid synthesis from isoprene units it has been shown that condensation of limonene (46) with senecioyl chloride in the presence of stannic chloride, followed by dehydrochlorination, provides a new simple synthetic route to a mixture of cis- (47) and frans-atlantones (48).23a Using acetyl chloride instead of senecioyl chloride in the synthetic sequence provides a C12 trisnor-sesquiterpenoid (49) which co-occurs with trans-atlantone in the essential oil of Cedrus atlantica.23b... 

The synthesis starts with the addition of senecioyl chloride (6.96) to isoprene (6.97). The acyl cation derived from the acid chloride adds to isoprene with a high degree of regioselectivity, for reasons which will be explained in the next paragraph. The carbocation produced by addition of the senecioyl ion to isoprene is trapped by the chloride anion to give... 

Friedel-Crafts reaction between senecioyl chloride (6.96) and d-limonene (6.102) in the presence of stannic chloride at low temperature, gave a-atlantone in one step, along with the isomeric ketones... 

Having verified the stereoisomeric purity of alcohol 1, a portion was converted to the chiral pheromone, (5)-(+)-lavandulyl senecioate 2a (78% yield), by treatment wiA senecioyl chloride and pyridine in ether 16). 

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