2- cyclopropylmethanols

A three-step protocol has been applied to obtain homoallylic carbanions from cyclopropylmethanol derivatives by regioselective opening of intermediate cyclopropyllithiums. ... 

Cyclopropanes have been used to test the reactivity of oxidizing enzymes. Thus, while the monooxygenase enzyme from Methylococcus capsulatus oxidizes cyclopropane 3 to cyclopropanol 4, on the other hand methylcyclopropane 1 a is oxidized to cyclopropylmethanol 5, also without ring opening, Eq. (2) [6]. 

The enzyme chemistry of cyclopropylmethanols has been studied both as inhibitors and mechanistic probes [4, 47]. Thus, a series of alkylcyclopropyl-methanol derivatives have been proved as being inhibitors of horse liver alcohol dehydrogenase. There are two sites in the cyclopropylmethanol inhibitors able of reacting with nucleophiles ... 

The cyclopropylmethanol ancymidol 50, applied as soil drench or as a foliar spray, shortened the internodes of ornamental plants. Trials with cultivation of Chrysanthenum morifoUum, Euphorbia pulcherrina and Tulipa gesneriana have been described, Eq. (18) [49]. 

In all cases, the cleavage of the auxiliary could not be accomplished under acidic conditions due to the sensitivity of the cyclopropyhnethanol unit. Cleavage by ring contraction of the corresponding C-2 O-triflyl derivative afforded the cyclopropylmethanols in good yield (equation 72). ... 

Whenever the intermediate cyclobutyl cation has the same degree of substitution as the corresponding cyclopropylmethyl and/or but-3-enyl cation, ring opening with concomitant formation of but-3-enyl compounds can occur. Examples are the formation of mixtures of trans-2-methylcyclobutan-1-ol (6), (E -pent-S-en-l-ol [( )-7], (Z)-pent-3-en-l-ol f(Z)-71 and pent-4-en-2-ol (8) from both 1-cyclopropylmethanol (4)17 and /ra/i,v-2-methylcyclopropancmethanol... 

Oxiranyl carbanions undergo regioselective intramolecular substitution to give cyclo-propylmethoxide ions. Thus, epoxidation of y,<5-unsaturated active methylene and methine compounds followed by treatment with appropriate base provides substituted cyclopropylmethanols (equation 13)24. The use of chiral epoxides, e.g. prepared by... 

Sharpless epoxidation, leads to the formation of optically active cyclopropylmethanols (equation 14)25 26. The cyclization/ring opening of a-cyano-a-sulfonyl-y,<5-epoxycarbanion,... 

Arylmethylene)cyclopropylmethanols have been reported to react with acetonitrile in triflic acid to give ring-enlarged iV-(arylmethylidenecyclobutyl)acetamides921... 

Hu S, Dordick JS (2002) Highly Enantioselective Oxidation of cw-Cyclopropylmethanols to Corresponding Aldehydes Catalyzed by Chloroperoxidase. J Org Chem 67 314... 

Fluorination of 9-benzyloxy-2-(4-fluorobenzyl)-6-methoxy-3,4-dihy-dro-lH,8H-pyrido[l,2-a]pyrazine-l,8-dione with Selectfluor in the presence of Ce2C03 in MeCN at ambient temperature for 6 h provided 7-fluoro derivative. Reaction of 6-bromo-3,4-dihydro-lH,8H-pyrido[1,2-a]pyra-zine-l,8-diones with phenol cyclohexyl-, and cyclopropylmethanols in the presence of Ce2C03 in DMF in a sealed tube at 25-60 °C for 12-24 h afforded 6-phenoxy, 6-cyclohexyl-, and 6-cyclopropylmethoxy derivatives, respectively (06WOP2006/066414). 

The importance of enantiomerically pure cyclopropane derivatives has already been pointed out (see Sect. 2.1) and many examples of lipase- or esterase-catalyzed kinetic resolutions of cyclopropanes can be found in the literature, but, unfortunately, high E values are scarce [76-84]. For instance, several lipases were screened for their ability to perform a kinetic resolution of cyclopropylmethanols [85],... 

Aryl- and alkenyl-substituted oxiranes, when submitted to treatment with super-basic reagents, undergo a highly regio- and stereo-selective 3-exo-cyclization leading to cyclopropylmethanol derivatives (Scheme 46). The process has be applied to mono- and di-hydroxy-substituted substrates, thus leading to polyhydroxylated cyclopropanes.78... 

From three-membered rings In pro tic media, l-acyl-2-cyclopropene derivatives undergo a ring expansion reaction to cyclobutenols [7]. - Ring expansion of cyclopropylmethanols to fluorinated cyclobutans [8]. 

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... 

A variety of 1,2,3-triacyl- and 1,2,3-trisalkoxycarbonylcyclopropanes have been prepared from the corresponding acyl- or alkoxycarbonylmethylides, a-haloketones" " and a-halocarboxylic esters". The reactions of a-haloketones and a-halocarboxylic esters with three equivalents of sulfoxonium methylide afford cyclopropyl ketones and cyclopropa-necarboxylic esters, respectively (equation 99). The reagent prepared from CH2I2 and Zn/Cu reacts with a-hydroxyketones to give cyclopropylmethanols". ... 

However, direct metalation of unactivated cyclopropanes is not practical. Phenyl- and (l-alkynyl)cyclopropanes have been metalated at the 1-position with BuLi/t-BuOK and BuLi, respectively. Cyclopropylmethanols undergo preferential syn-lithiation with i-PrLi as shown in equation 121. In the reaction of bridged compounds carrying a... 

However, the intermediacy of a cyclopropylcarbene from a-elimination was ruled out by labelling experiments. The rearrangement is assumed to proceed by a bimolecular eliminative mechanismFor a recent convenient preparation of practically pure cyclobutene from cyclopropylmethanol, see Ref. 191. 

Cyclopropylmethanol derivatives bearing electronegative a-substituents have been prepared from the ring contraction of a-substituted bromocyclobutanes on heating in glacial acetic acid containing an excess of silver acetate (equation 179) . ... 

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