2-Cyclopropyl-l-

Sull onat 2-Cyclopropyl-l-methyl-ethenyl- Trifluoromethane F,l b. 1089 [(R — S0,),O +... 

Imidazolium 2-Cyclopropyl-l,3-dimethyl-4,5-dihydro- -iodid E15/2,2054 (4,5-H2 — imidazol + R-I)... 

Disiloxan 1,3-Bis-[2-cyan-ethyl]-tetramethyl- E18, 809 Ethan 2-Cyclopropyl-l-diazo-2-oxo-1-pentamethyldisilanyl- El 4b. 1278 (H - CO-R)... 

Propen 2-Cyclopropyl-l-(diethyl-methyl-silyloxy)- EI5/1, 407 (-CH-0-CO-CH3 + CO + R3SiH)... 

A similar solution of 2-cyclopropyl-l,l,l-trideuterio-2-propanol gives a similar spectrum except that a and h are each reduced to one-half their former area. 

The products are apparently formed by addition of the metallocyclopropene to unreacted cyclopropene to generate a 2-(cyclopropenyl)-l-metallocyclopropane followed by a rapid equilibration with the more stable 2-(cyclopropyl)-l-metallocyclopropene. This reacts with further cyclopropene to give 1,2-(dicyclopropyl)cyclopropene or may be protonated to l-(cyclo-propyl)cyclopropene and then isomerized to cyclopropylidenecyclopropane. 

Cyclopropylalkan-l-ones are obtained from l-alkoxy-2-cyclopropyl-l-alkenes and l-acetoxy-2-cyclopropylaIk-l-enes under protic conditions and 2-cyclopropyl-l-trimethyl-siloxyalk-l-enes using tetrabutylammonium fluoride. The yields are usually moderate. 

A 2-cyclopropyl-l,3-dithiane derivative reacted with butyllithium followed by fert-butyl-chlorodimethylsilane at low temperature to give the 2-rert-butyldimethylsilyl-2-cyclopropyl-l, 3-dithiane derivative in 36% yield. ... 

Cyclopropyl-l,l-dihaloethenes with or without an additional halogen atom attached to C2, are generally converted to alkynes by treatment with butyllithium. The yields were generally good. The structure of the products depended on the amount of butyllithium as well as how the reaction mixture was quenched. When more than 2 equivalents of base were employed and quenching was performed with water or alcohol, the corresponding acetylenylcyclopropane was formed. ° 1 s 16,1 s 19,1820 However, when more than 2 equivalents... 

Reaction of 2-cyclopropyl-l-methoxyethene with trimethyl orthoformate in the presence of boron trifluoride resulted in addition to give 2-cyclopropyl-l,l,3,3-tetramethoxypropane in 63% yield. " ... 

Cyclopentadienyl)-(2-cyclopropyl-l-oxo-ethyi)-dichloro-trimeihoxy-phosphanc- 1784... 

The a-allylpalladium intermediate 135a, which must be formed on coupling of l,3-dicyclopropyl-l,2-propadiene (134), with, for example, iodobenzene under palladium catalysis rapidly undergoes rearrangement to the homoaUylpalladium species 135b and subsequent P-hydride elimination to yield the 1,3,5-hexatriene 136 [152g,h]. This in turn undergoes [4 + 2] cycloaddition with an added dienophile to furnish the 3-(2-cyclopropyl-l-phenyl)cyclohexene derivatives 138 as a mixture of trans,trans- and ds,trows-diastereomers (Scheme 8.31). 

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