This document summarizes methods for epoxide bond formation and cleavage. It discusses several reactions for forming epoxide bonds asymmetrically including the Katsuki-Sharpless epoxidation, Corey-Chaykovsky reaction, and Jacobsen-Katsuki epoxidation. It also covers mechanisms and examples of epoxide ring opening reactions using azide, catalyzed by zinc perchlorate, and asymmetrically using carbon dioxide. Cleavage of epoxide bonds allows access to valuable compounds such as propranolol and naftopidil.

1. Epoxide Bond Formation and
Cleavage
Presented By
Gurudutt Dubey
M. Tech. (Pharm.) I Semester
Department of Pharmaceutical Technology (Process Chemistry)
National Institute of Pharmaceutical Education and Research, Mohali, Punjab (India)
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2. Epoxide Bond Formation
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3. KATSUKI-SHARPLESS ASYMMETRIC EPOXIDATION
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J. Am. Chem. Soc. 1980, 102, 5914

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Mechanism:
M= Ti R= i-Pr

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Clayden, J. Warren, S. Greeves, N. Wothers, P. Organic Chemistry, 2001, 1242
Formation of Active Complex

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Clayden, J. Warren, S. Greeves, N. Wothers, P. Organic Chemistry, 2001, 1242
Stereoselectivity:

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J. Am. Chem. Soc. 1962, 84, 867−868
COREY-CHAYKOVSKY REACTION
Mechanism :

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Preparation of Corey-Chaykovsky Reagent
Dimethyloxosulfonium methylide - known as the Corey Chaykovsky Reagent

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JACOBSEN-KATSUKI EPOXIDATION
J. Am. Chem. Soc. 1991, 113, 7063-7064

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PRILEZHAEV REACTION
Org. Lett. 2003, 5, 3787-3790
Mechanism :

11. Epoxide Bond cleavage
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Clayden, J. Warren, S. Greeves, N. Wothers, P. Organic Chemistry, 2001, 434
Epoxide ring opening by azide

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Ionic liquids/H2O systems for the reaction of epoxides with NaN3 :
a new protocol for the synthesis of 2-azidoalcohols
Tetrahedron Lett. 2005, 46, 6559-6562

14. Regioselective Ring Opening of Epoxides Using NaN3
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Tetrahedron Lett. 2004, 45, 7355–7358

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Polyepoxide-Opening Cascades Promoted by Water
Science. 2007, 317, 1189

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Mechanism:

17. Epoxide Ring Opening Catalyzed by Zinc(II) Perchlorate Hexahydrate
Mechanism:
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J. Org. Chem. 2007, 72, 10, 3719

18. Synthesis of (RS)/(R)-Propranolols and (RS)/(R)/(S)-Naftopidils
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J. Org. Chem. 2007, 72, 10, 3719

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Asymmetric Catalysis with CO2: Direct Synthesis of Optically Active
Propylene Carbonate from Racemic Epoxides
J. Am. Chem. Soc. 2004, 126, 3733

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Mechanism:

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