1,2-Cyclopropane-diol

Davis, B. R., Hinds, M. G. Clemmensen reduction. XII. The synthesis and acidolysis of some diaryl-substituted cyclopropane-1,2-diols. The possible involvement of a cyclopropyl cation. Aust. J. Chem. 1997, 50, 309-319. 

Cyclopropane-1,2-diols 1 are readily prepared in high yield by the electrochemical 1,3-coupling reaction of 1,3-diones. This reaction is a bielectronic process, whereby the hydroxylic solvent serves as proton donor. 

Yoshioka, M., Miyazoe, S., Hasegawa, T., Photochemical Reaction of 3 Hydroxy 1 (o methylaryl)alkan 1 ones. Formation of Cyclopropane 1,2 diols and Benzocyclobutenols through 3 Hydrogen and y Hydrogen Abstractions, J. Chem. Soc., Perkin Trans. 1 1993, 2781 2786. 

Miscellaneous Methods.—The electrochemical reduction of 1,3-diketones, PhCOCR 2 = H or alkyl, = alkyl or aryl), leads to cyclopropane-1,2-diols by a bielectronic process. In some cases stereoselective cyclization favours cis-diol formation and product yields are generally satisfactory. Electrochemical cyclization of 1,1-bisbromomethylcyclopropane affords spiropentane. ... 

The role of the alkali metal in complex metal hydride reductions is critical, - os and complexing this metal with a macrocyclic co-ordinator curtails the reaction. A full report on the stereoselectivity of the cathodic reduction of cycloalkanoncs to cycloalkanols has been published. The electrochemical reduction of 1,3-diketones yields cyclopropane-1,2-diols (27), often in good yields. ... 

Scheme 8.38 Reaction pathway of cis-cyclopropane-1,2-diol formation.

A number of vinyl cyclopropane diols upon treatment with Dess-Martin reagent and pyridine underwent oxidation accompanied by rearrangement to give formyl dihydro-oxepins [30] ... 

Chiral Alcohols and Lactones. HLAT) has been widely used for stereoselective oxidations of a variety of prochiral diols to lactones on a preparative scale. In most cases pro-(3) hydroxyl is oxidized irrespective of the substituents. The method is apphcable among others to tit-1,2-bis(hydroxymethyl) derivatives of cyclopropane, cyclobutane, cyclohexane, and cyclohexene. Resulting y-lactones are isolated in 68—90% yields and of 100% (164,165). 

Cyclopentene-l,2-diol, 42, 51 2-Cyclopentene-1,4-dione, 42, 36 2-Cycloeentene-1-one, 42, 38 2-Cycloeentenone, 42,38 Cyclopropane, bromo-, 43, 9 Cyclopropanecarboxylic add, conversion to bromocyclopropane, 43, 9... 

The Oxygenation of Vinyl Cyclopropanes as an Entry Into Stereoselective 1,3-Diol Synthesis," Feldman. K.S. SvnletL 1995, 217... 

Optical resolution methods with carane-3,4-diol are noteworthy for wide generality. Esters of various cyclopropane carboxylic acids with (1,S, 3A>,4A>,6A>)-carane-3,4-diol were prepared and all (lR)-isomers could easily be obtained by a simple silica gel column chromatography. 

Diols generally react with dichlorocarbene to produce a mixture of alkenes and chlorinated cyclopropanes or chloroalkanes, depending on the reaction conditions whereas, under phase-transfer catalysed conditions, the major products are the alkenes and epoxides produced by ring closure of the initial adduct (Scheme 7.20) [14]. When an excess of chloroform is used, further reaction of the alkenes with dichlorocarbene produces the cycloadducts. In addition to the formation of the alkene and epoxide, 1,2-dihydroxycyclooctane yields cyclooctanone, via a 1,2-hydride shift within the intermediate carbenium ion. 

The dimethanesulphonates of 1,3-diols also give cyclopropanes on reduction at a lead cathode in dimethylformamide [104]. The reaction involves reduction of one... 

Charette and coworkers have shown that the diastereoselective cyclopropanation of chiral allylic alcohols with gem-dizinc carbenoids proceeds with high diastereocontrol for protected 2-butene-1,4-diol derivatives (equation 63). The minimization of the A-1,3 strain and the formation of a zinc chelate in the product is believed to be responsible for... 

FIGURE 7. 1,2- and 1,3-diol derived chiral auxiharies for the cyclopropanation of acychc unsaturated carbonyl... 

Treatment of diethyl malonate and related compounds with 1,2-dihaloethane in the presence of base constitutes a classical method of cyclopropane synthesis296"300. The reaction can be conveniently carried out under PTC conditions. An improved method utilizing solid-liquid phase transfer catalysis has been reported298. The reaction of dimethyl or diethyl malonate with 1,2-dibromoalkanes except for 1,2-dibromethane tends to give only low yields of 2-alkylcyclopropane-l, 1-dicarboxylic esters. By the use of di-tm-butyl malonate, their preparations in satisfactory yields are realized (equation 134)297. The 2-alkylcyclopropane derivatives are also obtained from the reaction of dimethyl malonate and cyclic sulfates derived from alkane-1,2-diols (equation 135)301. Asymmetric synthesis... 

CYCLOPENTANONE SYNTHESIS, 66, 87, 92, 93 Cyclopentanone, 2-carbomethoxy-3-vinyl, 66, 56 Cyclopentanone, 2-ethenyl-2-methyl (88729-76-4), 66, 94 Cyclopentene (142-29-0), 67, 157 4-Cyclopentene-1,3-diol, monoacetate, cis-, 67, 114 2-Cyclopenten-1-one, 4,4-dimethyl-, 67, 121,205 2-CYCLOPENTEN-1 -ONE, 3-METHYL-2-PENTYL-, 65, 26 CYCLOPROPANATION, 67, 176... 

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