View source for Chemistry:1,2,3,4,5-cyclopentanepentol

A '''cyclopentanepentol''', more precisely a '''1,2,3,4,5-cyclopentanepentol''' or '''cyclopentane-1,2,3,4,5-pentol''' is a [[Chemistry:Chemical compound|chemical compound]] with formula {{chem|C|5|H|10|O|5}} or {{chem|(–CHOH–)|5|}}, whose [[Physics:Molecule|molecule]] consists of a ring of five [[Chemistry:Carbon|carbon]] atoms (a [[Chemistry:Cyclopentane|cyclopentane]] skeleton), each connected to one [[Physics:Hydrogen|hydrogen]] and one [[Chemistry:Hydroxyl|hydroxyl]] group.<ref name=pubchem/>  There are four distinct stereoisomers with this same structure.<ref name=coll2005/>

The compound is a five-fold [[Chemistry:Alcohol|alcohol]] of cyclopentane, and technically a cyclic sugar alcohol (a cyclitol).  However it is very rarely found in nature, and therefore it has received much less attention than the ubiquitous six-carbon version, [[Chemistry:Inositol|inositol]].<ref name=angy1970xxxii/>

==Isomers==

There are four distinct stereoisomers of cyclopentane-1,2,3,4,5-pentol, distinguished by the position of the hydroxyls relative to the mean plane of the ring.  All have a plane of symmetry, and therefore are not chiral. One naming convention for the isomers labels each carbon number 1-5 with "α" for the side of the ring plane with most hydroxyls (three or more), and "β" for the other side.  Another convention lists the hydroxyls on the majority side and then those on the minority side, with the two groups separated by a slash (and a "0" is written when the second list would be empty).<ref name=iupac1968/>  

The four possible isomers are:<ref name=coll2005/>

* '''1α,2α,3α,4α,5α''', '''1,2,3,4,5/0''', or '''all-''cis''''' (all hydroxyls on the same side). CAS 34322-89-9. Long needles, melting point 283 °C (darkens ar 220 °C).<ref name=coll2005/><ref name=cocu1971/>

* '''1α,2α,3α,4α,5β''' or '''1,2,3,4/5'''. CAS 18939-02-1.<ref name=coll2005/> Soluble in hot [[Astronomy:Ethanol|ethanol]].<ref name=angy1970xxxii/> Melting point 220 °C<ref name=angy1970xxxii/> or 209-210 °C.<ref name=wolc1970/> Obtained by [[Chemistry:Solvolysis|solvolysis]] of two tetra-O-acetyl-O-tosylcyclopentanepentol,<ref name=angy1970xxxii/> and also by hydroxylation of 3,4,5-trihydroxy-1-cyclopentenes.<ref name=wolc1970/>

* '''1α,2α,3α,4β,5β''' or '''1,2,3/4,5'''. CAS 18939-07-6.<ref name=coll2005/> Soluble in ethanol.<ref name=angy1970xxxii/> Melting point 168-169 °C,<ref name=angy1970xxxii/> or 176 °C.<ref name=wolc1970/>  Obtained by deamination of (1,4/2,3,5)-5-amino-1,3-di-O-acetyl-2,3-O-cyclohexylidene-l,2,3,4-cycopentanetetrol,<ref name=angy1970xxxii/> and also by hydroxylation of 3,4,5-trihydroxy-1-cyclopentenes.<ref name=wolc1970/>

* '''1α,2α,3β,4α,5β''' or '''1,2,4/3,5'''. CAS 57784-52-8.<ref name=coll2005/> Melting point 149.5-150.5 °C.<ref name=angy1970xxxii/> Obtained from cyclopent-4-ene-1,3/2-trio1 by [[Chemistry:Epoxide|epoxidation]] and subsequent [[Chemistry:Hydrolysis|hydrolysis]],<ref name=sable1963/> and also by acid hydrolysis of an anhydro-cyclopentanepentol, DL-1,2-anhydro-4,5-O-cyclohexylidene-1,2,3/4,5-cyclopentanepentol.<ref name=angy1970xxxii/>

The last three isomers interconvert by heating them at about 104 °C with 95% [[Chemistry:Acetic acid|acetic acid]] in the presence of a strong acid. The conversion between 1,2,3,4/5 and 1,2,3/4,5 is faster and entails the hydrogen and hydroxyl switching places on either of the two carbon atoms located between an "α" and a "β" position.  The formation of 1,2,4/3,5 is much slower and equilibrium is reached only after many days. The relative stabilities are 1,2,4/3,5 > 1,2,3/4,5 > 1,2,3,4/5, with equilibrium ratios 72 : 17.5 : 10.5.<ref name=angy1970xxxii/>

The isomers can be identified qualitatively by their mobility in paper ionophoresis in a solution of [[Chemistry:Calcium acetate|calcium acetate]] and [[Chemistry:Acetic acid|acetic acid]], and revealed with a manganese sulfate/[[Chemistry:Potassium permanganate|potassium permanganate]] reagent. The mobilities of the isomers, relative to that of ''cis''-inositol, are 0.95 (12345/0), 0.44 (1234/5), 0.18 (123/45), and 0.04 (124/35).  The variation is attributed to the formation of chelates with the [[Chemistry:Calcium|calcium]] cations, with varying strengths depending on the number of hydroxyl pairs that can bind to the cation.<ref name=angy1979xi/> Similar results can be obtained with [[Chemistry:Lanthanum|lanthanum]] cations and [[Thin-layer chromatography|thin-layer chromatography]].<ref name=angy1985xiv/>

==Derivatives and natural occurrences==

Many [[Chemistry:Ester|ester]]s are known, such as pentabenzoyls<ref name=coll2005/> and pentaacetyls.<ref name=angy1970xxxii/>

Trteatment of the derivative 3,4,5-tri-O-acetyl-1,2-O-ethylidene-(1,2,4/3,5)-cyclopentanepentol with [[Chemistry:Triphenylcarbenium|triphenylcarbenium]] tetrafluoroborate  {{chem|[(C|6|H|5|)|3|C|]|+}}{{chem|[BF|4|]|−}} to yield the cation 3,4,5-tri-O-acetyl-(1,2,4/3,5)-cyclopentanepentol-1,2-O-acetoxonium, which exhibits a peculiar 10-stage cyclic rearrangement.<ref name=paul1969/>

Cyclopentanepentols form dihydrogen[[Chemistry:Phosphate|phosphate]] esters analogous to inositol's [[Chemistry:Phytic acid|phytic acid]] esters.<ref name=flem1999/>

The related compound 1,2,3,4,5-pentakis(hydroxymethyl)-cyclopentane (a colourless viscous oil, soluble in ''tert''-butanol and DMSO) was synthesized in 1985 by L. M. Tolbert and others.  It was hoped that dehydrative [[Chemistry:Dimer|dimer]]ization of this product would yield [[Chemistry:Dodecahedrane|dodecahedrane]].<ref name=tolb1985/>

Organic compounds similar (and possibly mimicking) glycoglycerolipids, with a 1,2,4/3,5-cyclopentanepentol group connected to the [[Chemistry:Glycerol|glycerol]] core in place of the [[Chemistry:Sugar|sugar]] group, have been found in several genera of marine sponges with widely separate ranges.<ref name=const1993/><ref name=koba1993/><ref name=ishi1993/><ref name=fatto1997/><ref name=kim1999/><ref name=liu2011/>

Calditol is a substance found in the archaeobacteria of the order ''Sulfolobales''.  It is an [[Chemistry:Ether|ether]] that can be viewed as the condensation of [[Chemistry:Glycerol|glycerol]] and cyclopentane-1α,2,2,3α,4α,5β-hexol (a cyclopentanepentol with an extra hydroxyl on carbon 2), forming an ether bridge –O– between the respective 1-carbons.<ref name=bler2001/>

==History==
The 1,2,4/3,5 isomer was brifly described in 1963 by H. Z. Sable and others.<ref name=sable1963/> In 1968, T. Posternak reported observation of 1,2,3,4/5 and 1,2,3/4,5, without the synthesis method.<ref name=post1968/> Better synthesis methods for these three were published by S. J. Angyal and B. M. Luttrell in 1970.<ref name=angy1970xxxii/> Alternative methods for 1,2,3,4/5 and 1,2,3/4,5 were published in the same year by G. Wolczunowicz and others.<ref name=wolc1970/> The remaining all-''cis'' isomer (1,2,3,4,5/0) was synthesized in 1971 by F. G. Cocu and others.<ref name=cocu1971/>

==See also==
* [[Chemistry:Cyclopentanepentone|cyclopentanepentone]] 

==References==

<references>

<ref name=pubchem>(2019) [https://pubchem.ncbi.nlm.nih.gov/compound/1_2_3_4_5-Cyclopentanepentol Entry 552295: 1,2,3,4-Cyclopentanepentol]. Page at the PubChem website, accessed on 2019-07-23.</ref>

<ref name=coll2005>Peter M. Collins (2005): ''[https://books.google.com.br/books?id=jw3NBQAAQBAJ&lpg=PA268&pg=PA268 Dictionary of Carbohydrates]'', 2nd edition, page 268. CRC Press, 1304 pages. {{isbn|9780849377655}}</ref>

<ref name=angy1970xxxii>S. J.  Angyal and B. M.  Luttrell (1970): "Cyclitols. XXXII. Cyclopentanepentols". ''Australian Journal of Chemistry'', volume 23, issue 9, pages 1831-1838. {[doi|https://doi.org/10.1071/CH9701831}}</ref>

<ref name=angy1979xi>S. J.  Angyal and J. A. Mills (1979): "Complexes of Carbohydrates with Metal Cations. XI. Paper Electrophoresis of Polyols in Solutions of Calcium Ions". ''Australian Journal of Chemistry'', volume 32, issue 9, pages 1993–2001. {{doi|10.1071/CH9791993}}</ref>

<ref name=angy1985xiv>S. J.  Angyal and J. A. Mills (1985): "Complexes of Carbohydrates with Metal Cations. XIV. Separation of Sugars and Alditols by Means of Their Lanthanum Complexes". ''Australian Journal of Chemistry'', volume 38, issue 8, pages 1279–1285. {{doi|10.1071/CH9851279}}</ref>

<ref name=sable1963>H. Z. Sable, Thelma Anderson, Bernadine Tolbert, Th. Posternak (1963): "Recherches dans la série des cyclitols XXXIII. Sur quelques cyclitols dérivés du cyclopentane". ''Helvetica Chimica Acta'', volume 46, issue 4, pages 1157–1165. {{doi|10.1002/hlca.19630460410}}</ref>

<ref name=iupac1968>CON and CBN IUPAC Commissions on Nomenclature (1968): "The Nomenclature of Cyclitols - Tentative Rules".  ''European Journal of Biochemistry'', volume 5, pages 1-12.  {{doi|10.1111/j.1432-1033.1968.tb00328.x}}</ref>

<ref name=post1968>T. Posternak, and G. Wolczunovicz (1968): "Two new cyclopentanepentols". ''Naturwissenschaften'', volume 55, issue 2, pages 82–83.{{doi|10.1007/BF00599491}}</ref>

<ref name=const1993>V. Costantino, E. Fattorusso, and A. Mangoni (1993): "Isolation of five-membered cyclitol glycolipids, crasserides: unique glycerides from the sponge ''Pseudoceratina crassa''" ''Journal of Organic Chemistry'', volume 58, issue 1, pages 186–191. {{doi|10.1021/jo00053a034}}</ref>

<ref name=koba1993>Jun'Ichi Kobayashi,  Chun-Min Zeng  and  Masami Ishibashi (1993): "Keruffaride, a new all-''cis''cyclopentanepentol-containing metabolite from the okinawan marine sponge ''luffariella'' sp.". ''Journal of the Chemical Society, Chemical Communications'', volume 1993, issue 1, pages 79–81. {{doi|10.1039/C39930000079}}</ref>   

<ref name=ishi1993>Masami Ishibashi, Chun-min Zeng, Jun'ichi Kobayashi (1993): "Keruffaride: Structure Revision and Isolation from Plural Genera of Okinawan Marine Sponges".  ''Journal of Natural Products'', volume 56, issue 10, pages 1856-1860. {{doi|10.1021/np50100a033}}</ref>

<ref name=fatto1997>E. Fattorusso, A. Mangoni (1997) "Marine Glycolipids".  In ''Fortschritte der Chemie organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products'', volume 72, pp 215-301. {{doi|10.1007/978-3-7091-6527-0_3}} {{isbn|978-3-7091-7342-8}}</ref>

<ref name=liu2011>Yonghong Liu, Jee H. Jung, Tunhai Xu, Lijuan Long, Xiuping Lin, Hao Yin, Bin Yang, Xue-Feng Zhou, and Xianwen Yang (2011): "New cyclitol derivative from a sponge ''Sarcotragus'' species". ''Natural Product Research'', volume 25, issue 6, pages 648–652. {{doi|10.1080/14786419.2010.490213}}</ref>

<ref name=kim1999>Dong-Kyoo Kim, Young Ja Lim. Jung Sun Kim, Jong Hee Park, Nam Deuk Kim, Kwang Sik Im, Jongki Hong, Jee H. Jung (1999) "A Cyclitol Derivative as a Replication Inhibitor from the Marine Sponge ''Petrosia'' sp. ''Journal of Natural Products'', volume 62, issue 5, pages 773-776. {{doi|10.1021/np9804785}}</ref>

<ref name=paul1969>H. Paulsen, H. Behre (1969): "Cyclorearrangement of 3,4,5‐Tri‐O‐acetyl‐(1,2,4/3,5)‐cyclopentanepentol‐1,2‐O‐acetoxonium Tetrafluoroborate". ''Angewandte chemie - International Edition'', volume 8, issue 11, pages 887–887.{{doi|10.1002/anie.196908871}}</ref>

<ref name=wolc1970>G. Wolczunowicz, L. Bors, F. Cocu, Th. Posternak (1970): "Recherches dans la série des cyclitols, XLI. Synthèses de deux cyclopentane‐pentols". ''Helvetica Chimica Acta'', volume 53, issue 8, pages 2288-2295. {{doi|10.1002/hlca.19700530843}}</ref>

<ref name=cocu1971>F. G. Cocu, T. Posternak (1971): ''Helvetica Chimica Acta'', volume 54, pages 1676-.</ref>

<ref name=bler2001>Yves Blériot, Edouard Untersteller, Benoît Fritz, and Pierre Sinaÿ (2001): "Total Synthesis of Calditol: Structural Clarification of this Typical Component of Archaea Order ''Sulfolobales''". ''Chemistry: A European Journal'', volume 8, issue 1, pages 240-246. {{doi|10.1002/1521-3765(20020104)8:1<240::AID-CHEM240>3.0.CO;2-G}}</ref>

<ref name=flem1999>Marc Felemez, Gilbert Schlewer, David J. Jenkins, Vanessa Correa, Colin W. Taylor, Barry V. L. Potter, and Bernard Spiess (1999): "Inframolecular studies of the protonation of 1D-1,2,4/3,5-cyclopentanepentaol 1,3,4-trisphosphate, a ring-contracted analogue of 1D-''myo''-inositol 1,4,5-trisphosphate".  ''Carbohydrate Research'', volume 322, issues 1–2, pages 95-101. {{doi|10.1016/S0008-6215(99)00193-7}}</ref>

<ref name=tolb1985>Laren M. Tolbert, J. Carlin Gregory, Carolyn P. Brock (1985): "''cis'',''cis'',''cis'',''cis''-1,2,3,4,5-Pentakis(hydroxymethyl)-cyclopentane". ''Journal of Organic Chemistry'', volume 50, issue 4, pages 548-548. {{doi|10.1021/jo00204a030}}</ref>

</references>

[[Category:Polyols]]

{{Sourceattribution|1,2,3,4,5-cyclopentanepentol|1}}