Formal protection of vinylepoxides via stereospecific chlorohydrin formation

Synlett

Volumn , Issue 8, 1999, Pages 1243-1244

  Daviu, Noemí ^a   Delgado, Antonio ^b   Llebaria, Amadeu ^a  

^a DEPARTMENT OF ENVIRONMENTAL CHEMISTRY   (Spain)

^b UNIVERSITY OF BARCELONA   (Spain)

Author keywords

Epoxides; Nitrogen; Ring closure; Ring opening; Stereoselectivity

Indexed keywords

ALPHA CHLOROHYDRIN; EPOXIDE; VINYL DERIVATIVE;

ARTICLE; CHEMICAL ANALYSIS; CHEMICAL REACTION; CHEMICAL STRUCTURE; STEREOCHEMISTRY; STEREOSPECIFICITY;

EID: 0032765423     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: 10.1055/s-1999-2801     Document Type: Article

References (14)

1. Unpublished results.
2. Greene, T.W.; Wuts, P.G.M. Protective Groups in Organic Synthesis; John Wiley and Sons, Inc. New York, 1991, pp. 328-329.
3. -1) 3372 (OH,NH), 3088, 2978, 2923, 1695, 1535. Elemental Analysis. Calculated. C, 50.96%, H, 7.70%; N, 5.94%; Cl, 15.04%. Found: C, 50.90%, H, 7.88%; N, 5.86%; Cl, 14.89%
4. This unexpected reaction was observed in an attempt to deprotect the N-Boc group with TMSCl-phenol according to: a) Kaiser, E.; Tam, J.P.; Kubiak, T.M.; Merrifield, R.B. Tetrahedron Lett. 1988, 29, 303-306.
5. b) Lee, S.G.; Yoon, Y.J.; Shin, S.C.; Lee, B.Y.; Cho, S.D.; Kim, S.K.; Lee, J.H. Heterocycles 1997, 45, 701-706. We later found that phenol was not required for chlorohydrin formation.
6. Vinyl epoxides undergo regio-and stereoselective ring opening at the allylic position with heteroatom nucleophiles; Lindström, U.M.; Somfai, P., Synthesis 1998, 109-117 and references therein.
7. For a different aproach to structurally related chlorohydrins and their transformation to vinylepoxides see: a) Hu, S.; Jayaram, S.; Ochlschlager, A.C. J. Org. Chem. 1996, 61, 7513-7520.
8. b) Hetweck, C.; Goerls, H.; Boland, W. J. Chem. Soc., Chem. Commun. 1988, 1955-1956.
9. Epoxide cleavage to halohydrin by halosilanes is known but usually requires the presence of promoters or catalysts: a) Denmark, S.E.; Barsanti, P.A., Wong, K.-T.; Stavenger, R.A. J. Org. Chem. 1998, 63, 2428-2429.
10. b) Garrett, C.E.; Fu, G.C. J. Org. Chem. 1997, 62, 4534-4535.
11. c) Bonini, C. Righi, G. Synthesis 1994, 225-238.
12. d) Iqbal, J.; Khan, M.A.; Ahmad, S. Synth. Commun. 1989, 19, 641-644.
13. e) Andrews, G.C.; Crawford, T.C. Tetrahedron Lett. 1981, 22, 3803-3806 and references therein. However, examples of this transformation in vinyloxiranes are scarce and usually less selective than the method described here; see for example: Addy, J.K.; Parker, R.E. J. Chem. Soc. 1965, 644 and reference 5c.
14. e) Andrews, G.C.; Crawford, T.C. Tetrahedron Lett. 1981, 22, 3803-3806 and references therein. However, examples of this transformation in vinyloxiranes are scarce and usually less selective than the method described here; see for example: Addy, J.K.; Parker, R.E. J. Chem. Soc. 1965, 644 and reference 5c.