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Optically Active Epoxy Diols by Titanium‐Catalyzed Oxidation of Enantiomerically Enriched Hydroperoxy and Hydroxy Homoallylic Alcohols
Author(s) -
Adam Waldemar,
Korb Marion N.,
SahaMöller Chantu R.
Publication year - 1998
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/(sici)1099-0690(199805)1998:5<907::aid-ejoc907>3.0.co;2-f
Subject(s) - chemistry , diastereomer , diol , enantiomer , alcohol , catalysis , epoxy , titanium , optically active , organic chemistry , alcohol oxidation , enantioselective synthesis , enantiomeric excess , epoxide
The Ti‐catalyzed epoxidation of optically active ( S , S )‐hydroperoxy homoallylic alcohols 2 affords the epoxy diol ( S , R , S )‐ 4 in high diastereoselectivity (d.r. up to 95:5), while the optically active hydroxy homoallylic alcohols ( R , R )‐ 3 are epoxidized by the β‐hydroperoxy alcohol 5 under titanium catalysis to the corresponding epoxy ( R , S , R )‐diol 4 in a diastereomeric ratio up to > 99:1. This high diastereoselectivity is rationalized in terms of a rigid template for the oxygen transfer, in which the hydroperoxy alcohol 2 or 5 is ligated tridentately and the diol 3 bound bidentately to the titanium metal. Through these oxidative routes, both enantiomeric epoxy diols 4 are conveniently accessible.