ISSN:
0170-2041
Schlagwort(e):
1,3-Dioxolanes
;
1,3-Oxazolidines
;
α-Oxocarboxylic acids
;
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Reactions of Trialkylsilyl Trifluoromethanesulfonates XI. - Synthesis of α-Oxocarboxylic Acid Derivatives from 2-O-Functionalized Trimethylsilyl Ketene AcetalsThe 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 esters 15 with trifluoroacetic acid anhydride/DMAP/pyridine.
Zusätzliches Material:
11 Tab.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/jlac.1992199201104
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