I´m not an expert but I think you can determine which conformation you have with NOESY. With the same experiment or maybe HNMR (if each conformer shows different signals) performed at different temperatures you might observe at some point both conformers with their signals very well defined, and at other temperatures broad signals that indicate you are close to the required energy for the conformational change. I hope this is helpful for you.

http://www.ochem4free.info/YQcr3l7Abrssp/03-Conform.pdf

http://www.columbia.edu/itc/chemistry/chem-c140499/chemgate/module_organic.pdf

These will help you !

Nice links (:

Thanks everyone for the valuable information.

variable temperature NMR is helpful.It is similar to to the process of finding the rotamers for which we dissolve the rotamers in DMSO and then we take the NMR.

By dnmr. (dynamic nmr)

By h-nmr

By NMR. There are three types of information you can get from NMR, proton-proton coupling constants, NOEs, and carbon chemical shifts. The axial-axial, axial-equatorial, and equatorial-equatorial proton-proton coupling constants are different and will give you clues on what you have, specially if you have substituents in the cyclohexane that will minimize the overlapping of proton signals from the cyclohexane. NOE will give you information on the spacial disposition of the protons and if you have substituents such a methyl, the NOE will tell you if it is equarial or axial. The carbon chemical shifts can also tell you that. There are important effects, specially the gamma gauche effect, that make distinct chemical shifts for the carbons in the ring and the substitutents like a methyl to be axial or equatorial. Check out the book K. Pihlaja and E. Kleinpeter, Carbon-13 NMR Chemical Shifts in Structure and Stereochemical Analysis, Wiley-VCH, New York, 1994. If you want to observe transitions, you will have to change the temperature to be able to "freeze" those conformations. Good luck!

Well, everyone else seems to have covered your question exceptionally well. The classic experiment is with C6D11H at temperatures gradually increasing from around -100 C. At such low temperatures, the NMR can distinguish between the axial and equatorial conformer of the single H and gives two sharp peaks each integrating for 1H which gradually coalesce into a single peak at around -60 C because the "ring flip" is happening faster than the NMR can distinguish between the axial and equatorial conformation of the H. Deuterium is invisible in 1-H NMR.

Yes. Use VT H NMR and, at low temperature, look for what is referred to as "W coupling": a long-range coupling between the equatorial protons on C1 and C3 (for example). In other words, a "4 bond coupling".

From the value of dihedral angle and coupling constant you can identify whether is chair form or boat form.

All the friends gave good answers and suggestions. I suggest that you study the stereochemistry book by Eliel, pages 686 to 708, chapter no 11. you can found the answer.

By 1HNMR at low temperature one can distinguish axial and equatorial protons.

List of Publications

1- Synthesis of benzo[1,2-b:5,4-b]difuranyl-triazoles, oxadiazoles, thiazolidione, thiadiazoles,and the use of DNA in evaluation of their biological activity,Phosphorus, Sulufer and Silicon, 179: 1577-1593, (2004). E.M. Keshk, A.A. Abu-Hashem, M.M. Girges, A.H. Abd EL-Rahman and F.A. Badria .

2- BIANNUAL Conference on chemistry, Cairo, 1--4 March 2004, organised by the department of chemistry, faculty of science, Cairo University, CHEM .03,1--3 MARCH 2004. Synthesis of novel heterocyclic compounds containing benzodifuran nucleus: reactions of Benzo[1,2-b:5,4-b]difuran-2-carbohy-dazides. E.M. Keshk, A.A. Abu-Hashem, M.M.Girges and A.H. Abd EL-Rahman.

3- Synthesis and Anti-Oxidant Activity of Novel pyrimido[4,5-b]quinolin-4-one Derivatives with a New Ring System., Phosphorus, Sulfur, Silicon and the Related Elements, 182: 2009 (2007). A.B.A. El-Gazzar, A.M. Gaafar, M.M. Youssef, A.A. Abu-Hashem and F.A. Badria.

4- Synthesis and Anti-Oxidant, Anti-Inflammatory and Analgesic Activity of Novel Polycyclic Pyrimido[4,5-b]quinolines, Phosphorus, Sulfur, Silicon and the Related Elements. 184:379-405(2009). A.B. El-Gazzar, H.N.Hafez , A.A. Abu-Hashem and A. S. Aly .

5- Design and Synthesis of Azolopyrimidoquinolines, pyrimidoquin- azolines as Anti-Oxidant, Anti-Inflammatory and Analgesic Activities., European J. of Medicinal chemistry. 44: 609-624 (2009). A.B.A. El-Gazzar, A.M.S. Youssef, M.M. Youssef, A. A. Abu-Hashem and F.A. Badria.

6- The 3 rd International Conference of Chemical Industries Research Division, under the theme "Chemical Industries: Role and future Aspects "National Research Centre, Cairo, Egypt, December 16---18 (2008). Synthesis of Pyrazolyl-Triazolyl-Thiazolyl,Pyrimido[4,5-b]quinoline derivatives and Pharmacological Activites as Anti-Oxidant. Ameen Ali Abu-Hashem and F.A.Badria.

7- 10Th International Conference on Chemistry and its Role in Development ICCRD10 "Chemistry Department, Mansoura University and Sharm EL-Sheikh, Faculty of Scince, Egypt, March 16---21 (2009). Synthesis,Anti-Oxidant, Anti-Inflammatory and Analgesic Activities of Some New Pyrrolo[2,3-d]Thiazolo[3,2-a] Pyrimidine derivatives. A. A. Abu-Hashem, M.M.Youssef , F.A.Badria .

8- Egyptian Second International Conference in Chemistry: Chemistry for Human Needs 9-12 November (2009). Hurghada (The Egyptian Chemical Society, Founded 1928, Member of the Union of Arab Chemists). “Synthesis and Evaluation of Some New Pyrimido [3', 2':4, 5]Thiazolo [2,3-b] Quinoxalin Derivatives as Anti-oxidant, Antiinflammatoryand Analgesic Activities". A. A. Abu-Hashem .

9- Synthesis of 3 - ((2, 4-dichlorophenoxy) methyl)-1, 2, 4-triazolo (thiadiazoles and thiadiazines) as anti-inflammatory and molluscicidal agents European Journal of Medicinal Chemistry.45: 1906-1911 (2010). M.F. El Shehry, A.A. Abu-Hashem and E.M. El-Telbani.

10- Synthesis of some new pyrimido [2′, 1′: 2, 3] thiazolo[4,5-b]quinoxaline derivatives as anti-inflammatory and analgesic agents. European Journal of Medicinal Chemistry. 45: 1976-1981(2010). A. A. Abu-Hashem , M. AGouda , F.A.Badria.

11- Design and synthesis of novel thiophenecarbohydrazide, thienopyrazole and thienopyrimidine derivatives as antioxidant and antitumor agents. Acta Pharm. 60: 311–323(2010). A.A. Abu-Hashem , M.F. El Shehry, F.A.Badria.

12- The 4 rd International Conference of Chemical Industries Research Division, under the theme "Chemical Industries: Role and future Aspects "National Research Centre, Cairo, Egypt, Nov. 30th -Dec. 2nd, (2010). Synthesis of New Pyrimidoquinoline derivatives .Ameen Ali Abu-Hashem.

13 - Novel Synthesis of Fused pyrazolopyrimidines and C-Nucleosides of Thienopyrimidone with Expected Antimicrobial Activity. Egypt. J. Chem. 53, No.4,pp.527-540(2010).H. A. R. Hussein, Kh. M. Abu-Zied and A. A. Abu-Hashem.

14- Synthesis, Characterization, Antioxidant and Antitumor Evaluation of Some New Thiazolidine and Thiazolidinone. Arch. Pharm. Chem. Life Sci., 344, Issue 3, pages 170–177 (2011). Moustafa A. Gouda1 and Ameen A. Abu-Hashem. DOI: 10.1002/ardp.201000165.

15- Synthesis, Antioxidant, Antitumor Activities of Some New Thiazolo pyrimidines, Pyrrolothiazolopyrimidines and triazolopyrrolothiazolo pyrimidines Derivatives. J. Chinese. Chemical Society. 58, 1-8 (2011). A.A. Abu-Hashem, Mohamed M. Youssef and Hoda A. R. Hussein.

16- Synthetic utility of bifunctional thiophene derivatives and antimicrobial evaluation of the newly synthesized agents. Monatshefte fur Chemie - Chemical Monthly. 142, 539 - 545 (2011). A. A. Abu-Hashem, Khadiga M. Abu-Zied, Mohamed F. El-Shehry. DOI 10.1007/s00706-011-0456-z.

17- Synthesis of New Visnagen and Khellin Furochromone Pyrimidine Derivatives and Their Anti-Inflammatory and Analgesic Activity. Molecules. 16, 1956 -1972 (2011). Ameen Ali Abu-Hashem, Mohamed M. Yousef. doi:10.3390/ molecules16031956.

18- Synthesis, Anti-inflammatory and Analgesic Evaluation of Certain New 3a, 4, 9, 9a -Tetrahydro-4, 9-benzenobenz[f]isoindole-1,3-diones. 344, Issue 8, 543–551, August (2011), Arch. Pharm. Chem. Life Sci., 000, 1–9 (2011). A. A. Abu-Hashem and Mustafa Ahmed Gouda. DOI: 10.1002/ardp.201100020.

19- Synthesis and anti-microbial activity of some 1- substituted amino- 4, 6-di methyl-2-oxo-pyridine-3-carbonitrile derivatives. European Journal of Medicinal Chemistry. 46, 5057- 5064 (2011). Rizk E. Khidre, Ameen A. Abu-Hashem , Mohamed El-Shazly. doi:10.1016/j.ejmech.2011.08.018.

20- Synthesis of New Pyrazole, Triazole, Thiazolidine, -Pyrimido[4,5-b]quinoline Derivatives with Potential Antitumor Activity. Archives of Pharmacal Research., 35, No.3, 437-445 (2012). Ameen Ali Abu-Hashem, Ahmed S. Aly. DOI 10.1007/s12272-012-0306-5.

21- The Fourth International Chemistry Conference Riyadh- Kingdom of Saudi Arabia 19-21, November (2011), 23-25 Thu Elhejah 1432 H Chemistry Department Faculty Science – King Saud University." Design and Synthesis of Novel Spiro-Pyrimidine derivatives as Antioxidant and Antitumor Agents.” Ameen Ali Abu-Hashem.

22- An eco-friendly procedure for the efficient synthesis of arylidinemalononitriles and 4, 4'-(arylmethylene) bis (3-methyl-1- phenyl-1H-pyrazol-5-ols) in aqueous media. Green Chemistry Letters and Reviews, First article, 1-7(2012). Moustafa A. Gouda and Ameen A. Abu-Hashem. DOI:10.1080/17518253.2011.613858.

23- Furochromones Extract from a Plant Ammi visnaga with the Preparation of New Visnagenone, Khellinone Derivatives and Study Their effect as Anticancer Pharmacology. The 27th Meeting of Saudi Biological Society, Econnmics of Environment and Natural Resources , Jazan City at Jazan University

13-15 Rabia Alakeer, 1433 H (6-8 March, 2012), Ameen Ali Abu-Hashem.

This experiment is close to absolute zero, it is difficult to conduct.

NMR is best but if you dont have NMR just read book "Eliel, pages 686 to 708, chapter no 11" you can see paper posted by

Mr.Ameen Abuhashem.... if you dont get any paper just mail me paper title(DOI)& your mail id

NMR is the best tools to detect the conformation of cyclohexane. As per my knowledge 1H NMR does at very lowest temperature e.g. -70 to -90 degree centigrade.

ooops m too late, but proton NMR is the best way

IR spectra aslo helpfull to identify conformational.

NMR is the best instument for detecting the Chair and boat form of Cyclo hexane at negative temperature -40 to -60 deg