
%0 Journal Article
%A Buckland, SJ 
%A Halton, B 
%A Mei, Q 
%A Stang, PJ 
%T Studies in the Cycloproparene Series: Reactions of Alkylidenecycloproparenes With Electrophiles
%J Australian Journal of Chemistry
%D 1987/08/01
%V 40
%N 8
%P 1375-1387
%K 
%R https://doi.org/10.1071/CH9871375
%U https://www.publish.csiro.au/paper/CH9871375 
%X The addition of an electrophile to the alkylidenecycloproparenes (2a-d) is dominated by capture at the exocyclic centre with formation of the corresponding cycloproparenyl cation, e.g. (15). Subsequent reaction with the counter ion is usually accompanied by cleavage of the three-membered ring. Thus compounds (2) give the ethanones (4) with aqueous acids whilst anhydrous acetic acid yields the vinyl acetates (5). Silver(1)-catalysed methanolysis of (2) leads to vinyl ethers (6); the alkyne (7) is formed only from (2d) which carries a vinylic proton. Brominations and bromine water additions lead to products of ring expansion (8)-(10) or ring cleavage (11)-(14) depending upon the conditions employed. These latter reactions demonstrate a delicate balance between cycloproparenylcarbinyl cation formation and cleavage of the three-membered ring. 
