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Stereoselective Synthesis of Medium‐Sized Cyclic Compounds by Means of Tandem Reactions of a Cyclic Oxosulfonium Ylide with Acetates of Baylis−Hillman Adducts
Author(s) -
Akiyama Hitoshi,
Fujimoto Tetsuya,
Ohshima Katsuyoshi,
Hoshino Kenji,
Saito Yuko,
Okamoto Ayu,
Yamamoto Iwao,
Kakehi Akikazu,
Iriye Ryozo
Publication year - 2001
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 - 10.1002/1099-0690(200106)2001:12<2265::aid-ejoc2265>3.0.co;2-8
Subject(s) - ylide , chemistry , intramolecular force , adduct , methylene , cycloheptene , cycloaddition , medicinal chemistry , stereoselectivity , organic chemistry , stereochemistry , catalysis
Treatment of a five‐membered cyclic oxosulfonium ylide 3 with β‐acetoxy‐α‐methylene ketones in the presence of two equimolar amounts of base afforded the cycloheptene oxide derivatives 7a−i as single stereoisomers in 19−77% yields. The products were considered to form through a Michael‐type addition of the ylide, followed by elimination of the acetoxy group and an intramolecular Corey−Chaykovsky reaction. On the other hand, the same treatment, when using a six‐membered oxosulfonium ylide, gave the corresponding cyclooctene oxide derivatives in moderate yields, with the products formed in a ca. 4:1 mixture of stereoisomers, a fact correlated with differences in the configuration of the sulfur atom in the sulfinyl group.