Synthesis of a set of isomeric 2,4,6-triarylmorpholines and 2,6-diaryloxathianes from the corresponding 1,5-diols has been described. The method provides an efficient route to six-membered heterocycles from acyclic diols and is found to be better than Mitsunobu procedure in yield and waste management. In a related study, the ring contraction of pyranone to two isomeric cyclopentenone derivatives through
Reaktionen von 1,4-Pentadien-3-onen, 11. Mitt.: Zur Reaktion von Dialkylketonen mit aromatischen Aldehyden
作者:Hans-Hartwig Otto、Ulrich Ebner
DOI:10.1002/ardp.19763091205
日期:——
Aus Dialkylketonen 1 werden durch Kondensation mitaromatischen Aldehyden alkylsubstituierte 3‐Butenone 2 erhalten, die bei nochmaliger Kondensation mit geeigneten Aldehyden alkylsubstituierte 1,4‐Pentadien‐3‐one 3 ergeben. Das aus Diäthylketon erhältliche 2a ergibt bei weiterer Reaktion nicht 3, sondern Tetrahydro‐4‐pyranone 5, aus denen durch starkes Alkali entweder 2,4‐dialkylsubstituierte 1,4‐Pentadien‐3‐one
The rates of oximeformation of 41 heterocyclic ketones have been measured at 5 °C in aqueous alcoholic solution buffered at pH 6.85. The data indicate an overall second-order reaction, first order each in ketone and hydroxylamine. In all cases investigated the reaction appears to be irreversible under the experimental conditions employed. Increased steric retardation is observed as steric crowding