5-(2,2-dimethyl-l,3-dioxolan-4-yl)-3-[(tetrahydropyranyloxy)methyl]-2-isoxazoline, 90410-13-2; 5(S)-

SummaryPrecursors of 3-pyridylnitrene and 2- and 4-pyrimidinylcarbenes all afford mixtures of 2- and 3-cyanopyrroles on flash vacuum thermolysis, but 3-cyanopyrroles are the first-formed products. 3-Quinolylnitrenes and 4-quinazolinylcarbenes similarly afford 3-cyanoindoles. 2-Pyrimidinylcarbenes rearrange to 3-pyridylnitrenes, but 4-pyrimidinylcarbenes and 4-quinazolinylcarbenes do not necessarily rearrange to the corresponding 3-pyridylnitrenes or 3-quinolylnitrenes. The ring contraction reactions are interpreted in terms of ring opening of either the nitrenes or the diazacycloheptatetraenes to nitrile ylides.

Aus Meldrum‐Säure (I) erhält man durch Kondensation mit Orthoester (II) und Aminen (III) die Aminomethylenverbindungen (IV).