141666-30-0Relevant articles and documents
Reactions of Trialkylsilyl Trifluoromethanesulfonates XI. - Synthesis of α-Oxocarboxylic Acid Derivatives from 2-O-Functionalized Trimethylsilyl Ketene Acetals
Simchen, Gerhard,Siegl, Gerald
, p. 607 - 614 (2007/10/02)
The cyclic ketene acetals 3, 5 are prepared from the dioxolanone 2 resp. the oxazolidinediones 4 by silylation with trimethylsilyl triflate (1)/triethylamine.In an aldol addition/Peterson olefination reaction catalysed by 1 the ketene acetals 3, 5 yield the (E/Z)-benzylidene derivatives 7, 12, 13 in reaction with aromatic aldehydes 6.In a side reaction the α-(trimethylsilyl)benzylidene derivatives 8 are formed from 3 and 6.Compounds 7 can be hydrolysed to yield α-ketocarboxylic acids 14.The latter are also obtained via β-elimination of trimethylsilanol from 2,3-bis(trimethylsiloxy)carboxylic acid anhydride/DMAP/pyridine. Key Words: 1,3-Dioxolanes / 1,3-Oxazolidines / α-Oxocarboxylic acids