Organic Chemistry Using Weakly Electrophilic Salts: Efficient Formation of O,O-Mixed, O,S- and N,O-Acetals
Hiromichi Fujioka,* Takashi Okitsu, Takuya Ohnaka, Ruichuan Li, Ozora Kubo, Kazuhisa Okamoto, Yoshinari Sawama and Yasuyuki Kita*
*Graduate School of Pharmaceutical Sciences, Osaka University, 1-6, Yamada-oka, Suita, Osaka 565-0871, Japan, Email: fujiokaphs.osaka-u.ac.jp, kitaphs.osaka-u.ac.jp
H. Fujioka, T. Okitsu, T. Ohnaka, R. Li, O. Kubo, K. Okamoto, Y. Sawama, Y. Kita, J. Org. Chem., 2007, 72, 7898-7902.
DOI: 10.1021/jo071187g (free Supporting Information)
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Treatment of symmetrical O,O-acetals with TESOTf and 2,4,6-collidine formed weakly electrophilic collidinium salts. Subsequent addition of nucleophiles, such as alcohols, lithium thioxide, and sodium azide, to the salts afforded the corresponding O,O-mixed, O,S- and N,O-acetals in good yields.
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