Wolf-Ulrich Nickel

En route to tetra-t-butylethylene

Abstract Triene 22 was synthesized and converted by two different routes to the tetraaldehyde 27, the first “non-bridged” derivative of 1. An X-ray analysis of 27 reveals that the CC bond is twisted by 28.6°. Attempts to prepare 1 from 27 failed, thus far. Addition of t-butyllithium to 13, subsequent reaction with ethylene oxide and further reactions led to the highly strained tri-t-butylethylethylene 33; according to force field calculations 33 has the largest fragmentation strain of all synthesized hydrocarbons of this type.

Synthese von verbrückten derivaten des tetra-tert. Butylethens

Abstract The sterically hindered alkenes 6 and 7 , which are potential precursors for the synthesis of tetra-tert.butylethene, were prepared. Attempts at the synthesis of 5 via the thiadiazoline route failed.

Sterisch gehinderte Alkene. VI: Auf dem Weg zum Tetra-tert.butylethen

Zusammenfassung Several potential precursors of 1 were synthesized, among them the tetraaldehyde 10 , tri-tert.butylmethylethene ( 16 ) and the diketone 18 .

Sterisch gehinderte Alkene, VII Röntgenstrukturanalyse und Reaktionen des Tetrakis-(2-formyl-2-propyl)ethens

Abstract The tetraaldehyde {=1} was synthesized by ozonation of the triene {=3}. The C=C-bond in {=1} is twisted by 28.6° and the CC-bond and the allylic bond lengths are significantly elongated to 135.7 and 155.5–159.7 pm, resp.