Ketone, dicyclopropyl

Es stellte sich heraus, da6 Dicyclopropyl-keton ein brauchbarer Sensibilisator fiir die Dimerisierung von Norbomen zu den Dimeren (46) und (47) ist, da die Umsetzung bis zu 46% ohne Nebenproduktbildung ablauft (34). 

Alkyl cyclopropyl ketones or dicyclopropyl ketones in fluorosulfuric acid/sulfuryl chloride fluoride at about -90 °C undergo O-protonation to a-hydroxycyclopropyl-carbinyl cations (equation 7). These cations are essentially protonated ketones, as the positive charge heavily resides on the oxygen atom16. X-ray structural studies have also been carried out on hydroxycyclopropylcarbinyl cation salts, since they are easily obtained as crystalline materials17. 

Condensation of dicyclopropyl ketone with diethyl succinate using sodium hydride as base gave... 

The condenser is arranged for downward distillation, and a total of 650 ml. of ketone-water mixture is collected as distillate. Sufficient potassium carbonate is added to saturate the aqueous layer, and about 130 ml. of ketone is separated. The aqueous layer is extracted with three 100-ml. portions of ether, and the combined ether and ketone layers are dried over 25 g. of anhydrous magnesium sulfate. The product remaining after removal of the ether is distilled through an efficient column. The yield of dicyclopropyl ketone boiling at 72-74°/33 mm., a 5 1.4654, is 114-121 g. (52-55%) (Note 9). 

This procedure is a modification of one recently described in the literature.3 The first step is based on early work of Fittig 4 and Volhard5 as modified by Spencer and Wright.2 The third step, ring closure of a 7-haloketone, is well known.5-6 Dicyclopropyl ketone was reported to form in small amounts from the decarboxylation of cyclopropanecarboxylic acid over thoria,7 but there is some doubt3 about the product. Dicyclopropyl ketone is available in research quantities from the Aldrich Chemical Company, Milwaukee 12, Wisconsin, and from Columbia Organic Chemicals, Inc., Columbia, South Carolina. 

The BH.i/BF.vOEt2 reagent reduces not only aryl ketones and aldehydes, but also cyclopropyl aryl or dicyclopropyl ketones to the methylene compounds without opening or rearrangement in the cyclopropyl unit (equation 21). ... 

Formation of 170 from the reaction of dicyclopropyl ketone with Na was attributed to formation of a dianion which rearranged and added to another molecule of ketone (equation 36). An alternative route would involve cleavage of a radical anion and then reduction. 

A synthesis of dicyclopropyl ketone developed by Hart and co-workers involves in the first step a sodium methoxide-catalyzed self-condensation of y-butyrolactone (1) to the dimeric product (2). Solvent methanol is removed by distillation, eventually... 

Similarly, the oxime of dicyclopropyl ketone (25) is converted into A-cyclopropylcyclo-propanecarboxamide (26) in 65% yield when benzenesulfonyl chloride in dioxane is employed. ... 

Reaction of 2-chloro-l,l-dicyclopropylethene (35, prepared from dicyclopropyl ketone by chloroolefination) with butyllithium in tetrahydrofuran between — 110°C and + 20 °C affords dicyclopropylethyne (36) in 83% yield together with some 1,1-dicyclopropylhex-l-ene (37,10% yield). Hydrogenation of 36 over a Lindlar catalyst proceeded almost quantitatively and stereospecifically to give (Z)-l,2-dicyclopropylethene (38). 

Lactones have been converted to (hydroxyalkyljcyclopropyl phenyl ketones on reaction with phenylmagnesium bromide and phenyllithium. Reductive dimerization of ethyl cyclo-propanecarboxylate with sodium gave l,2-dicyclopropylethane-l,2-dione in 69% yield when thionyl chloride treatment was carried out prior to hydrolytic workup, and to dicyclopropyl ketone in 74% yield, when workup included sodium bromate treatment. A related reaction occurred during thermolysis of 6,6-dimethyl-5,7-dioxaspiro[2.5]octane-4,8-dione to give dispiro[2.1.2.1. ]octane-4,8-dione. ... 

A number of alkyl cyclopropyl ketones have been converted to the corresponding 1 -cyclopropyl-1-alkenamines by treatment with various amines,in most cases in the presence of titanium(IV) chloride, The yields were generally moderate. Dicyclopropyl ketone (1) reacted under standard conditions to give product 2 in which one of the cyclopropanes has undergone ring opening,... 

Dicyclopropyl ketone reacted with dimethyltitanium(IV) chloride under inert conditions to give the product of dimethylation, 2,2-dicyclopropylpropane, in 84% yield.A similar reaction took place on reaction of cyclopropyldiphenylsufonium tetrafluoroborate with cyclo-propanecarbaldehyde under basic conditions giving 2-cyclopropylcyclobutanone. ... 

Dicyclomine hydrochloride Dicyclopentadiene Dicyclopentyl ether Dicyclopropyl ketone... 

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