Evidence for concerted processes in the course of the homoallenylic transposition
作者:Chahinez Aouf、Nicolas Galy、Maurice Santelli
DOI:10.1016/j.tet.2013.02.048
日期:2013.4
The hydrolysis of β-allenic tosylates produces mainly 2-methylenecyclobutanols resulting from a homoallenylic participation along with isomeric 2-methylenecyclobutanol minor products coming from a 1234–1243 rearrangement. Structures of various cyclopropylvinyl carbocations involved in the course of the hydrolysis have been determined by computational studies. For acyclic tosylates, the hydrolysis of
Prop-2-ynyl- and propadienyl-lithium reagents. Regiocontrolled synthesis of allenic compounds
作者:Chanh Huynh、G�rard Linstrumelle
DOI:10.1039/c39830001133
日期:——
Direct proof for the rearrangement of the prop-2-ynyl-lithium (2) into the propadienyl-lithium (4) is provided by the formation of the 1,3-disubstituted alleniccompounds(7).
Solvolysis of acyclic allenic tosylates shows that the allene group participates strongly to give cyclopropyl ketones and methylenecyclobutanols. Whenever C4 and C5 of the 3-methyl penta-1,2 dien-5-yl system carry different substituents, an apparent exchange of position between them occurs during the cyclisation.