- Gold-catalyzed rearrangement of allylic oxonium ylides: Efficient synthesis of highly functionalized dihydrofuran-3-ones
-
"Diazo" not needed: The title reaction results in the rearrangement of oxonium ylides, which were prepared from readily available homopropargylic allylic ethers instead of diazo compounds, through two different mechanisms: a concerted 2,3-sigmatropic rearrangement, or a stepwise 1,4-allyl migration followed by a Claisen rearrangement (see scheme). Copyright
- Fu, Junkai,Shang, Hai,Wang, Zhaofeng,Chang, Le,Shao, Wenbing,Yang, Zhen,Tang, Yefeng
-
supporting information
p. 4198 - 4202
(2013/05/08)
-
- The first radical method for the introduction of an ethynyl group using a silicon tether and its application to the synthesis of 2′-deoxy-2′-C-ethynylnucleosides
-
A novel radical method for the stereoselective introduction of an ethynyl group has been developed. When a solution of ethynyldimethylsilyl (EDMS) or [2-(trimethylsilyl)ethynyl]dimethylsilyl (TEDMS) ethers of trans-2-iodoindanol was treated with Et3
- Sukeda, Makoto,Ichikawa, Satoshi,Matsuda, Akira,Shuto, Satoshi
-
p. 3465 - 3475
(2007/10/03)
-
- Conformational effects on lipase-mediated acylations of 2-substituted cyclohexanols
-
Lipase-mediated acetylations of trans- and cis-2-substituted cyclohexanols gave the corresponding (1R)-cyclohexyl acetates and (1S)-cyclohexanols in high yields and ee, but c-4-tert-butyl-c-2-ethenyl-r-1-cyclohexanol was unreactive owing to the steric interaction between the axial OH group and the axial H atoms at the 3- and 5-positions. In the cis-isomer the OH group occupies an equatorial position to bind to the lipase, and less bulky axial alkenyl and alkynyl groups might not so much prevent acetylations than an alkyl group.
- Tanikaga, Rikuhei,Matsumoto, Yoshimasa,Sakaguchi, Maki,Koyama, Yohei,Ono, Kentaro
-
p. 6781 - 6783
(2007/10/03)
-
- Thermal and lewis acid catalyzed intramolecular ene reactions of allenylsilanes
-
Intramolecular ene reactions of allenylsilanes can be effected with a variety of imines, aldehydes and alkenes as enophiles, forming five and six membered rings. These reactions are cis stereoselective in all cases studied, and appear to proceed via a concerted, pericyclic process. The cycloadditions all generally occur under mild thermal conditions and some involving imino enophiles can also be effected at lower temperatures using Lewis acid catalysis.
- Weinreb, Steven M.,Smith, Daniel T.,Jin, Jian
-
p. 509 - 521
(2007/10/03)
-