Unraveling the Mechanism of Tricyclic Bis-spiroketal Formation from Diyne Diol by DFT Study

Author(s): Kamlesh Sharma*.

Journal Name: Letters in Organic Chemistry

Volume 16 , Issue 5 , 2019

Become EABM
Become Reviewer

Graphical Abstract:


Abstract:

The mechanism of addition of nucleophiles to the π-acid complexed alkynes has been studied successfully by the assessment of energy of intermediates and activation parameters. To elucidate the origin of stereoselectivity and predict the reaction pathways, the geometry optimizations of reactants, products, intermediates and transition states, were calculated by using density functional theory (DFT) at the B3LYP/6-31+G(d) method. The reaction mechanism of hydration of alkynes in the catalyzed synthesis of bis-spiroketal by DFT calculations is explored. The pyranyl enol ether was formed regioselectively by the first ring closure. Further, bis-enol ether was formed by second 6-exodig addition. Then, dehydration, followed by dehydrative ring closure finally gave bis-spiroketal product. It is concluded that one of the most feasible reaction pathways comprises pyranyl enol ether and bis-enol ether formation as intermediates. The final cyclization step of product formation is endothermic. In terms of stereochemistry, the trans-product is found to be energetically more stable than cisproduct and hence supports the electivity of the reaction.

Keywords: Reaction mechanism, DFT, regioselectivity, stereoselectivity, tricyclic bis-spiroketal, alkynes.

[1]
Brimble, M.A.; Furkert, D.P. Curr. Org. Chem., 2003, 7, 1461-1484.
[2]
Stivala, C.E.; Zakarian, A. J. Am. Chem. Soc., 2008, 130, 3774-3776.
[3]
Li, Y.; Zhou, F.; Forsyth, C.J. Angew. Chem. Int. Ed., 2007, 46, 279-282.
[4]
Meilert, K.; Brimble, M.A. Org. Biomol. Chem., 2006, 4, 2184-2192.
[5]
Hao, J.; Matsuura, F.; Kishi, Y.; Kita, M.; Uemura, D.; Asai, N.; Iwashita, T. J. Am. Chem. Soc., 2006, 128, 7742-7743.
[6]
Perron, F.; Albizati, K.F. Chem. Rev., 1989, 89, 1617-1661.
[7]
Aho, J.E.; Pihko, P.M.; Rissa, T.K. Chem. Rev., 2005, 105, 4406-4440.
[8]
Tu, Y.Q.; Hübener, A.; Zhang, H.; Moore, C.J.; Fletcher, M.T.; Hayes, P.; Dettner, K.; Francke, W.; McErlean, C.S.P.; Kitching, W. Synthesis, 2000, 13, 1956-1978.
[9]
Furkert, D.P.; Brimble, M.A. Org. Lett., 2002, 4, 3655-3658.
[10]
McCauley, J.A.; Nagasawa, K.; Lander, P.A.; Mischke, S.G.; Semones, M.A.; Kishi, Y. J. Am. Chem. Soc., 1998, 120, 7647-7648.
[11]
Geisler, L.K.; Nguyen, S.; Forsyth, C.J. Org. Lett., 2004, 6, 4159-4162.
[12]
Li, Y.; Zhou, F.; Forsyth, C.J. Angew. Chem., 2006, 119, 283-286.
[13]
Tofi, M.; Montagnon, T.; Georgiou, T.; Vassilikogiannakis, G. Org. Biomol. Chem., 2007, 5, 772-777.
[14]
Weldon, A.J.; Tschumper, G.S. J. Org. Chem., 2006, 71, 9212-9216.
[15]
Nieto-Oberhuber, C.; López, S.; Jiménez-Núñez, E.; Echavarren, A.M. Chem. Eur. J., 2006, 12, 5916-5923.
[16]
Volchkov, I.; Sharma, K.; Cho, E.J.; Lee, D. Chem. Asian J., 2011, 6, 1961-1966.
[17]
Paioti, P.H.S.; Ketcham, J.M.; Aponick, A. Org. Lett., 2014, 16, 5320-5323.
[18]
Sharma, K.; Lal, B. J. Steroid Biochem. Mol. Biol., 2008, 110, 278-283.
[19]
Sharma, K.; Kubli-Garfias, C. J. Mol. Model., 2005, 11, 135-140.
[20]
Spartan’08 Version 1.2.0, Wavefunction, Inc., 18401 Von Karman Ave., Suite 370, Irvine, CA 92612, USA.
[21]
Becke, A.D. J. Chem. Phys., 1993, 98, 5648-5652.
[22]
Khan, S.A.; Asiri, A.M.; Kumar, S.; Sharma, K. J. Fluoresc., 2015, 25, 503-518.
[23]
Asiri, A.M.; Khan, S.A.; Marwani, H.M.; Sharma, K. J. Fluoresc., 2015, 25, 1585-1593.
[24]
Hosseinnejad, T.; Fattahi, B.; Heravi, M.M. J. Mol. Model., 2015, 21, 264.
[25]
Zhixing, C. Theor. Chim. Acta, 1983, 62, 293-299.
[26]
Belting, V.; Krause, N. Org. Lett., 2006, 8, 4489-4492.


Rights & PermissionsPrintExport Cite as


Article Details

VOLUME: 16
ISSUE: 5
Year: 2019
Page: [392 - 395]
Pages: 4
DOI: 10.2174/1570178616666181130164235
Price: $58

Article Metrics

PDF: 22
HTML: 3