A mild and selective deprotection of p-methoxybenzyl (PMB) ether by magnesium bromide diethyl etherate-methyl sulfide

Tetrahedron Letters

Volumn 38, Issue 8, 1997, Pages 1443-1446

  Onoda, Toshihiko ^a   Shirai, Ryuichi ^a   Iwasaki, Shigeo ^a  

^a UNIVERSITY OF TOKYO   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

ALKANOL;

ARTICLE; DRUG SYNTHESIS; IN VITRO STUDY; METHODOLOGY; REACTION ANALYSIS;

EID: 0031584948     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(97)00043-9     Document Type: Article

References (25)

1. 1. (a) Greene, T. W. In Protective Groups in Organic Synthesis; John Wiley & Sons: New York, 1981; Chap. 1.
2. (b) Bhatt, M. V.; Kulkarni, S. U. Synthesis 1983, 249-282.
3. 2. (a) Oikawa, Y.; Yoshioka, T.; Yonemitsu, O. Tetrahedron Lett. 1982, 23, 885-888.
4. (b) Idem, Ibid. 1982, 23, 889-892.
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6. 3. Classon, B.; Garegg, P. J.; Samuelsson, B. Acta Chem. Scand. Ser. B, B38 1984, 419-422.
7. Other methods for the oxidative cleavage of PMB ethers have been reported: (a) Barton, D. H. R.; Magnus, P. D.; Smith, G.; Streckert, G.; Zurr, D. J. Chem. Soc., Perkin Trans. I 1972, 542-552.
8. (b) Schmidt, W.; Steckhan, E. Angew. Chem., Int. Ed. Engl. 1978, 17, 673-674.
9. (c) Weinreb, S. M.; Epling, G. A.; Comi, R.; Reitano, M. J. Org. Chem. 1975, 40, 1356-1358.
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11. (b) Idem, Tetrahedron 1996, 52, 14543-14562.
12. 5. (a) White, J. D.; Amedio, J. C.; J. Org. Chem. 1989, 54, 736-738.
13. (b) Yan, L.; Kahne, D.; Synlett 1995, 523-524.
14. 6. Fuji, K.; Node, M. Yuki Gosei Kagaku Kyokai Shi 1984, 42, 193-205.
15. Several combined systems of a hard Lewis acid and a soft nucleophile have been reported for cleavage of a variety of carbon-oxygen single bonds. For example, see: (a) Tsuji, T.; Kataoka, T.; Yoshioka, M.; Sendo, Y.; Nishitani, Y.; Hirai, S.; Maeda, T.; Nagata, W. Tetrahedron Lett. 1979, 20, 2793-2796.
16. (b) Fuji, K.; Ichikawa, K.; Node, M.; Fujita, E. J. Org. Chem. 1979, 44, 1661-1664.
17. (c) Olah, G. A.; Narang, S. C.; Balaram Gupta, B. G.; Malhotra, R. J. Org. Chem. 1979, 44, 1247-1251.
18. (d) Kiso, Y.; Ukawa, K.; Nakamura, S.; Ito, K.; Akita, T. Chem. Pharm. Bull. 1980, 28, 673-676.
19. 3, benzene, 20°C, 20 h (96%);
20. (b) 13, n-BuLi, THF, -78°C, 1 h, then 14, THF, -78-20°C, 15 h (85%)
21. 2 were the most suitable.
22. 2, freshly prepared from magnesium and dibromoethane in ether, gave a similar result.
23. 10. Fuji, K.; Kawabata, T.; Fujita, E. Chem. Pharm. Bull. 1980, 28, 3662-3664.
24. 11. Selective deprotection of PMB ether in the presence of benzyl ether has been reported: Akiyama, T.; Shima, H.; Ozaki, S. Synlett 1992, 415-416.
25. + 183.0844, found 183.0861.