results in the formation of the corresponding silyl enolethers or β-ketosilanes. The relative ratio of these products varies with the ylide conditions and the stability of ylide used. It is noteworthy that silyl enolethers were formed under the salt-free ylide conditions, and that β-ketosilanes were yielded in the presence of soluble inorganic salts in THF, selectively. The formation of both products
REACTION OF 1-TRIMETHYLSILYLCYCLOPROPYLLITHIUM DERIVATIVES WITH DICHLORO-METHYL METHYL ETHER. A NOVEL SYNTHESIS OF CYCLOPROPYL SILYL KETONES
作者:Tadashi Nakajima、Masaru Tanabe、Katsuhiko Ohno、Masahito Segi、Sohei Suga
DOI:10.1246/cl.1986.177
日期:1986.2.5
Treatment of 1-trimethylsilylcyclopropyllithium derivatives with dichloromethyl methyl ether affords the corresponding newcyclopropylsilylketones in moderate yield. This reaction involves the intramolecular 1,2-silicon shift from carbon to carbon.
Reaction of acylsilanes with α-sulfinyl carbanions: regioselective synthesis of silyl enol ethers
作者:Mitsunori Honda、Tadashi Nakajima、Maiko Okada、Keita Yamaguchi、Mitsuhiro Suda、Ko-Ki Kunimoto、Masahito Segi
DOI:10.1016/j.tetlet.2011.05.041
日期:2011.7
The reaction of acylsilanes with α-sulfinyl carbanions such as α-lithioalkyl sulfoxide is described. The reaction proceeds to give silylenolethers preferentially through the initial formation of the α-silyl alkoxide intermediates. In particular, the products derived from enolizable acylsilanes were the regio-defined silylenolethers that cannot be obtained by usual enolization of the corresponding
RING OPENING AND ENLARGEMENT OF CYCLOPROPYL TRIMETHYLSILYL KETONES BY ACIDS
作者:Tadashi Nakajima、Hiroyuki Miyaji、Masahito Segi、Sohei Suga
DOI:10.1246/cl.1986.181
日期:1986.2.5
The reaction of a series of cyclopropyl trimethylsilyl ketones with acids proceeds under milder conditions compared to that of their carbonanalogs to give either the ring opening products, 3-chloropropyl trimethylsilyl ketones, or the ringenlargement products, 2-trimethylsilyl-4,5-dihydrofuran derivatives.
Reaction of cyclopropylacylsilanes with sulfuric or triflic acid in aprotic solvent affords the corresponding cyclobutanone or 2-silyl-4,5-dihydrofuran derivatives, depending upon the substituents on the three-membered ring or acid used. The use of triflic acid results in the selective formation of the dihydrofurans.