Iodoolefinic polypropionate building blocks from vinyl silanes with control of geometry by solvent and by neighboring group participation

Tetrahedron Letters

Volumn 52, Issue 17, 2011, Pages 2115-2116

  Parker, Kathlyn A ^a   Denton, Richard W ^a  

^a STONY BROOK UNIVERSITY   (United States)

Author keywords

Anchimeric assistance; Iododesilylation; Polypropionate; Solvent effect; Vinyl iodide

Indexed keywords

DIMETHYL SULFOXIDE; HEXAFLUORO 2 PROPANOL; IODINE DERIVATIVE; SILANE DERIVATIVE; SOLVENT; VINYL DERIVATIVE;

ARTICLE; CHEMICAL STRUCTURE; DESILYLATION;

EID: 79953217665     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2010.11.001     Document Type: Article

References (15)

1. Nicolaou, K. C.; Bulger, P. G.; Sarlah, D. Angew. Chem., Int. Ed. 2005, 44, 4442.
2. Stamos, D. P.; Taylor, A. G.; Kishi, Y. Tetrahedron Lett. 1996, 37, 8647.
3. Ilardi, E. A.; Stivala, C. E.; Zakarian, A. Org. Lett. 2008, 10, 1727-1730.
4. Xie, Q.; Denton, R. W.; Parker, K. A. Org. Lett. 2008, 10, 5345-5348.
5. As part of an extensive study of solvent effects on the stereoselectivity of the halodesilylation of (E)-1-silyloctenes, Tamao had shown that NBS in DMF gave 1-bromooctenes with a high inversion: retention (Z:E) ratio; see: Tamao, K.; Akita, M.; Maeda, K.; Kumada, M. J. Org. Chem. 1987, 52, 1100.
6. Complex intermediates that contain trisubstituted (E)-olefins adjacent to a series of asymmetric centers are most often prepared from methyl acetylenes by hydrozirconation/iodination or hydrostannylation/iodination; see: (a) Hart, D. W.; Blackburn, T. F.; Schwartz, J. J. Am. Chem. Soc. 1975, 97, 679;
7. (b) Benechie, M.; Skrydstrup, T.; Khuong-Huu, F. Tetrahedron Lett. 1991, 32, 7535. They have also been prepared from (E)-vinyl silanes by iododesilyation with retention of geometry (our Refs. 2-4).
8. During the course of our work, Oguri and co-workers reported complete inversion of geometry in the iododesilylation of a (Z)-trisubstituted olefin, unsubstituted on the carbon chain, in DMF; see: Migita, A.; Shichijo, Y.; Oguri, H. i.; Watanabe, M.; Tokiwano, T.; Oikawa, H. Tetrahedron Lett. 2008, 49, 1021.
9. For total syntheses and biological activities of khafrefungin and its isomers, see: Shirokawa, S.; Shinoyama, M.; Ooi, I.; Hosokawa, S.; Nakazaki, A.; Kobayashi, S. Org. Lett. 2007, 9, 849. and references therein.
10. For leading references on tirandamycins A and B, see: Shiratani, T.; Kimura, K.; Yoshihara, K.; Hatakeyama, S.; Irie, H.; Miyashita, M. Chem. Commun. 1996, 21.
11. Each of these compounds was fully characterized.
12. 6 gave the dihydrooxasiline. Ring cleavage with methyllithium yielded hydroxy vinyl silane 5a. See: (a) Trost, B. M.; Ball, Z. T. J. Am. Chem. Soc. 2003, 125, 30;
13. (b) Mbaye, M. D.; Demerseman, B.; Renaud, J.-L.; Toupet, L.; Bruneau, C. Adv. Synth. Catal. 2004, 346, 835.
14. For additional evidence for this mechanism, see Refs. 2 and 3.
15. Acetate (Z)-1b was prepared by 9-BBN hydroboration of our siloxine precursor (Ref. 4), ring opening with methyllithium, selective protection of the primary hydroxyl group with TBSCl, and acetylation of the remaining secondary hydroxyl group.