Highly diastereoselective Markovnikov hydration of 3,4-dialkoxy-1-alkenes and 4,5-dialkoxy-2-alkenes via a hydroboration-oxidation process

Tetrahedron Letters

Volumn 40, Issue 45, 1999, Pages 7907-7910

  Jung, Michael E ^a   Karama, Usama ^a  

^a UNIVERSITY OF CALIFORNIA   (United States)

Author keywords

Allylic stereocontrol; Diastereoselective hydroboration oxidation; Markovnikov hydration

Indexed keywords

ALCOHOL DERIVATIVE; ALKENE DERIVATIVE; ALLYL COMPOUND;

ARTICLE; DIASTEREOISOMER; HYDRATION; OXIDATION; STEREOCHEMISTRY;

EID: 0033527681     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(99)01496-3     Document Type: Article

References (16)

1. Jung, M. E.; Nichols, C. J. Tetrahedron Lett. 1998, 39, 4615.
2. Nichols, C. J. PhD Thesis, UCLA, 1998. Since our research goal in this project was the total synthesis of 1, we did not spend the time to determine the structure of this undesired minor product.
3. For good reviews, see: (a) Brown, H. C.; Kramer, G. W.; Levy, A. B.; Midland, M. M. Organic Synthesis via Boranes; Wiley: New York, 1975.
4. (b) Brown, H. C. Boranes in Organic Synthesis; Cornell University Press: Ithaca, NY, 1972.
5. (c) Smith, K.; Pelter, A. In Comprehensive organic synthesis; Trost, B. M., Ed. Hydroboration of C=C and C=C. Pergamon: Oxford, 1991; Vol. 8, Chapter 3.10, p. 703.
6. (a) Brown, H. C.; Chen, J. C. J. Org. Chem. 1981, 46, 3978.
7. (b) Brown, H. C.; Unni, M. K. J. Am. Chem. Soc. 1968, 90, 2902.
8. (c) Brown, H. C.; Gallivan Jr., R. M. J. Am. Chem. Soc. 1968, 90, 2906.
9. (d) Brown, H. C.; Sharp, R. L. J. Am. Chem. Soc. 1968, 90, 2915. These authors report significant elimination of the allylic oxygen substituent, a process that we do not observe here.
10. 3
11. 2 symmetric 11b are easily distinguished by simple proton and carbon NMR.
12. The tribenzyl ethers derived from 21a and 25a each have a plane of symmetry and thus their proton and carbon NMR spectra are greatly simplified compared to those expected of the benzyl ethers derived from 21b and 25b.
13. 4 and NMO afforded mainly the diol in which the hydroxyls were added to the face opposite the allylic benzyl ether. Bis-benzylation afforded the enantiomer of the tetra benzyl ether formed from 22a. See: Babine, R. E. Tetrahedron Lett. 1986, 27, 5791.
14. (a) For a discussion of this 'inside-alkoxy' effect, see: Houk, K. N.; Moses, S. R.; Wu, Y.-D.; Rondan, N. G.; Jäger, V.; Schohe, R.; Fronczek, R. R. J. Am. Chem. Soc. 1984, 106, 3880.
15. (b) Cha, J. K.; Christ, W. J.; Kishi, Y. Tetrahedron Lett. 1983, 23, 3943.
16. (c) Stork, G.; Kahn, M. Tetrahedron Lett. 1983, 23, 3951.