Original scientific paper

Chemistry of 1,3-Dioxepins. 111. Dehydrohalogenation of 5,6-Dihalogen-1,3-Dioxepanes with Strong Bases

Mladen V. Proštenik ; PLIVA, Pharmaceutical and Chemical Works Zagreb
Miljenko Dumić ; PLIVA, Pharmaceutical and Chemical Works Zagreb
Ivan Butula ; Faculty of Pharmacy and Biochemistry, Zagreb, Croatia, Yugoslavia

Abstract

Dehydrohalogenation of 5,6-dihalogen-1,3-dioxepanes II with
KOH/MeOH or NaOCH3/MeOH under controlled reaction conditions
gave mainly 5-halogen-4,7-dihydro-1,3-dioxepines III. Further substitution
of vinylic-bromine in III whit KO-t-Bu/tert-BuOH or
KOH/MeOH led to corresponding 5-substituted-4,7-dihydro-1,3-
-dioxepines some of which underwent spontaneous isomerization
to 6,7-dihydro-1,3-dioxepines. Substitution of vinylic-bromine
appeared to follow an elimination-addition mechanism with initial
formation of an intermediate with a triple bond.

Keywords

Hrčak ID:

194164

URI

https://hrcak.srce.hr/194164

Publication date:

6.4.1984.

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