Cyclopropylmethanols synthesis

With regard to the reagents used in this type of cyclopropanation, 1,2-dibromoethane has been used most frequently. l-Bromo-2-chloroethane, however, may give better yields in some cases. 2-Chloroethylsulfonium iodide is used in the reaction of cyclic ketones to give the spiro derivatives . The use of vinylogous derivatives of 1,2-dihalides allows a synthesis of vinylcyclopropanes (equation 89) . (Chloromethyl)oxirane provides substituted cyclopropylmethanols (equation Oxiranes may also be used in place of... 

Cyclobutanol was obtained by deamination of (cyclopropylmethyl)amine in 40% yield. Cyclopropylmethanol was a major byproduct in this reaction. A more efficient synthesis of cyclobutanol is the acid-catalyzed rearrangement of cyclopropylmethanol with aqueous hydrochloric acid " cyclobutanol was obtained in 72% yield containing a trace of the allyl alcohol. This transformation forms the basis of an efficient cyclobutene synthesis. ... 

Fluorocyclobutanes 8 and 9 were prepared from 1 -substituted cyclopropylmethanol derivatives in good yield by reaction with diisopropylamine/potassium fluoride/polyhydrogen fluoride-pyridine complex. This transformation forms the basis for the synthesis of ( )-2-fluorograndisol from 2-(l-isopropenylcyclopropyl)-4-mesyloxybutan-2-ol (10). ... 

A full account has been given of the preparation of cyclopropylmethanols or cyclobutanols from y-epoxysulphones (Scheme 1). This useful method can also be applied to the synthesis of cyclopentanols from 5-epoxysulphones. The same idea has been used by Gaoni in a simple synthesis of bicyclo[1.1.0]butanes (6). a,j8-Unsaturated sulphones (7) undergo Michael attack by a-metallated nitriles leading to the cyclopropanes (8) as yet the method is limited to cases where R = Phor SR ... 

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