Cyclopropyl carboxamides

Using a mixture of 4-toluenesulfinic acid and triethylamine as the nucleophile in this procedure gave various A -[l-(4-tolylsulfonyl)cyclopropyl]carboxamides... 

V-3,7-Dimethyl-2,6-octadienyl cyclopropyl carboxamide 1779 N No safety concern... 

Another domino Michael addition/SN sequence has been elaborated by the group of de Meijere. It was discovered that upon basic treatment of 2-chloro-2-cyclopropyl-idenacetates 2-168 with carboxamides 2-169 in MeCN, 4-spirocyclopropane-anne-lated oxazoline-5-carboxylates 2-172 are formed (Scheme 2.40) [91]. As intermediates, the carbanion 2-170 and 2-171 can be proposed. 

The classical tin-lithium exchange reaction was first applied to cyclopropanes in the stereospecific transformation of 7- compound with BuLi in THF, at -95 °C vide supra). The retention of configuration in cyclopropyl tin-lithium exchange reactions has also been confirmed in monocyclic 2-metallacyclopropane carboxamides. More recently, this metal exchange reaction was used for the preparation of sensitive methylenecyclopropanes (equation 21). ... 

In subsequent investigations by others, Step 7 piperidine- and tetrahydro-2H-thiopyran-sulfonyl derivatives were prepared. These include l-cyclopropyl-N-hydroxy-4-[[4-[4-( 1 -ethylethoxy)-phenoxy] -phenyl]-sulfonyl] -4-piperidinecarboxamide hydrogen chloride, (III), (3) and tetrahydro-4-[[4-trifluoromethyloxy)-phenyl]sulfonyl]-2H-thiopyran-4-carboxamide, (IV), (4). 

The cleavage of alicyclic phenyl ketones generally leads to benzene and alicyclic carboxamides. Nevertheless, the use of 1-methyl cyclopropyl phenyl ketone yields benzamide and a cyclopropane. Using this property with a chiral compound, Imposimato and Walborsky (ref. 110) have shown that this reaction proceeds with retention of configuration (Fig. 20). 

The Schmidt reaction of cyclopropyl alkyl ketones is remarkably dependent on the strength of the acid used. Whereas the use of 83 % HjSO gives N-cyclopropylamides predominantly (74— 92 %), trichloroacetic acid yields unrearranged cyclopropane-carboxamides, Cyclopropyl ethers have been used for the production of alkoxy-containing polymers. ... 

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