Reference

Domino syntheses of five-, six- and seven-membered O-, N- and S-heterocycles from a-, b- and g-substituted carboxylic esters

Domino syntheses of five-, six- and seven-membered O-, N- and S-heterocycles from a-, b- and g-substituted carboxylic esters. Loeffler, J.Several substances are used for example 165337-05-3 and 41994-45-0 which are their cas registry numbers.; Schobert, R. (Inst. Org. Chem., Univ. Erlangen-Nuernberg, Erlangen D-91054, Germany). Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry, (23), 2799-2802 (English) 1996 Royal Society of Chemistry. CODEN: JCPRB4. ISSN: 0300-922X. DOCUMENT TYPE: Journal CA Section: 27 (Heterocyclic Compounds (One Hetero Atom)) By a one-pot procedure, tetronic acids, tetronates, coumarins, benzoxepinones and their N- and S-analogs are readily accessible from ketenylidenetriphenylphosphorane and carboxylic esters bearing OH, NHR or SH groups in an a-, b- or g-position by an addn./Wittig olefination/(Claisen rearrangement) sequence. This cascade can be controlled by temp. variation. Extension of this procedure by a further addn. step yielding annulated bisheterocycles such as the furoquinolone I is possible in some cases. .

A new method to generate a-aminoalkyl radicals

A new method to generate a-aminoalkyl radicals. Treatment of methyl a-amino seleno esters with hydride reagents. Synthesis of 6-azabicyclo[3.2.1]octanes by radical cyclization. Quirante, Josefina; Escolano, Carmen; Bonjoch, Josep (Faculty Pharmacy, University Barcelona, Barcelona 08028, Spain).There are some reagents with their cas registry numbers 187807-22-3 and 41994-45-0 are used in this study. Synlett, (2), 179-180 (English) 1997 Thieme. CODEN: SYNLES. ISSN: 0936-5214. DOCUMENT TYPE: Journal CA Section: 27 (Heterocyclic Compounds (One Hetero Atom)) A method to generate a-aminoalkyl radicals and its application to the synthesis of 6-azabicyclo[3.2.1.]octanes is described. On heating with Bu3SnH or (Me3Si)3SiH, a-amino seleno esters undergo decarbonylation of the initially formed acyl radical to give the corresponding a-amino radicals which were trapped intramolecularly with a double bond bearing an electron-withdrawing group. .