Reactions of azepinones with electrophiles

Tetrahedron Letters

Volumn 52, Issue 8, 2011, Pages 939-942

  Dubinina, Galyna G ^a,c   Chain, William J ^a,b  

^a UNIVERSITY OF HAWAII   (United States)

^b UNIVERSITY OF HAWAII CANCER CENTER   (United States)

^c SensoPath Technologies Inc   (United States)

Author keywords

Alkaloid; Alkyl halide; Alkylation; Azepinone; Epoxide; Isomerization; Ring contraction; Ring expansion; Synthesis

Indexed keywords

BENZODIAZEPINE DERIVATIVE; ELECTROPHILE; EPOXIDE; NITROGEN;

ALKYLATION; ARTICLE; CYCLOADDITION; ISOMERIZATION; RING OPENING;

EID: 78751580237     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2010.12.091     Document Type: Article

References (9)

1. G. Dubinina, W.Y. Yoshida, and W.J. Chain Tetrahedron Lett. 51 2010 5325 5327
2. M.J. Alves, and T.L. Gilchrist J. Chem. Soc., Perkin Trans. 1 1998 299 303
3. M.J. Alves, and T.L. Gilchrist Tetrahedron Lett. 39 1998 7579 7582
4. M.J. Alves, A.G. Fortes, and F.T. Costa Tetrahedron 62 2006 3095 3102
5. M.J. Alves, A.G. Fortes, F.T. Costa, and V.C.M. Duarte Tetrahedron 63 2007 11167 11173
6. S. Danishefsky, T. Kitahara, C.F. Yan, and J. Morris J. Am. Chem. Soc. 101 1979 6996 7000
7. S. Danishefsky, C.-F. Yan, R.K. Singh, R.B. Gammill, P.M. McCurry Jr., N. Fritsch, and J. Clardy J. Org. Chem. 101 1979 7001 7008
8. General procedure for alkylation and epoxide opening reactions with azepinone 1: anhydrous potassium carbonate (207 mg, 1.50 mmol, 3.00 equiv) and an electrophile (0.75 mmol, 1.50 equiv) were added sequentially to a stirred solution of azepinone 1 (91 mg, 0.50 mmol, 1 equiv) in 7 mL dimethylsulfoxide (0.07 M) at 23 °C. The resultant suspension was placed in an oil bath preheated to 60 °C and stirred at that temperature for 24 h, then was cooled and partitioned between saturated aqueous sodium chloride solution (20 mL) and ethyl acetate (20 mL). The layers were separated and the aqueous layer was extracted with ethyl acetate (3 × 10 mL). The combined organic layers were dried over anhydrous sodium sulfate and the dried solution was concentrated. The residue was purified by flash column chromatography (80% ethyl acetate-hexanes) to afford the alkylated product.
9. The ring contraction occurs with or without the inclusion of sodium bicarbonate.