Cyclopentane, synthesis

Cyclopentene-l-carboxaldehydes are obtained from cyclohexene precursors by the sequence cyclohexene - cyclohexane-1,2-diol -> open-chain dialdehyde - cyclopentane aldol. The main advantage of this ring contraction procedure is, that the regio-and stereoselectivity of the Diels-Alder synthesis of cyclohexene derivatives can be transferred to cyclopentane synthesis (G. Stork, 1953 G. BUchi, 1968). 

We shall concentrate in our short account of PG syntheses on solutions to both problems as provided in the literature. Some fundamentals of cyclopentane synthesis have been discussed in section 1.13.3 (see also 4.5.1). 

The vinylcyclopropane rearrangement is particularly valuable for cyclopentane synthesis. Aphidicolin (187), a most unusual antitumor agent, yields nicely to an analysis based on the concept of cyclopentanone annulation as outlined in Scheme 9... 

Cyclopentanes, synthesis, 66, 10 CYCLOPEKTANONE SYNTHESIS, 66, 87, 92, 93 Cyclopentanone, 2-carbomethoxy-3-vinyl, 66, 56 Cyclopentanone, 2-ethenyl-2-methyl (88729-76-4), 66, 94 2-CYCLOPENTEN-l-ONE, 3-METHYL-2-PENTYL-, 65, 26 Cyclopropane, l-trimethy1s1lyloxy-1-ethoxy-, 56, 44 Cyclopropanecarboxylic acid chloride, 66, 176... 

Related compound 70 gives 72 and hence 73 on addition to 71 in a useful cyclopentane synthesis.56 57 The mannitol-derived bis-epoxide 72 led to a mixture of 73 and 74, and 74 was used in the synthesis of the carbasugar epi-validatol 75.58... 

Chiral Cyclopentane Synthesis From Sugars Transformation of monosaccharides into enantiomerically pure penta- substituted cyclopentanes via fragmentation and nitrone-olefin dipolar cycloaddition. 

Feldman KS, Romanelli AL, Ruckle RE, Miller RF. Cyclopentane synthesis via free radical mediated addition of functionalized alkenes to substituted vinyl cyclopropanes. J. Am. Chem. Soc. 1988 110(10) 3300-3302. 

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