Diphenylsulfonium cyclopropylide

Sulfur ylides can also transfer substituted methylene units, such as isopropylidene (Entries 10 and 11) or cyclopropylidene (Entries 12 and 13). The oxaspiropentanes formed by reaction of aldehydes and ketones with diphenylsulfonium cyclopropylide are useful intermediates in a number of transformations such as acid-catalyzed rearrangement to cyclobutanones.285... 

Trialkylation of k etones. The silyl ether of a viny Icyclopropanol such as 1, obtained by reaction of a ketone with diphenylsulfonium cyclopropylide followed by silylation. 

Cyclobutanones have become very useful intermediates for synthesis since their introduction by Trost as a means of secoalkylation. The key element in the synthesis was diphenylsulfonium cyclopropylide (365) which is generated from its precursor diphenylcyclopropylsulfonium fluoroborate (364) by treatment with potassium hydroxide. 

ALKYLATION, w-ALLYLPALLADIUM COMPLEXES Palladium(II) chloride. ALKYLATION, GEMINAL Diphenylsulfonium cyclopropylide. 

Diphenylsulfonium cyclopropylide and the yllde derived from the N,N-dlmethyl salt of cyclopropylphenylsulfoxlmine reacts with a,0-unsaturated and g-dlmethylamino ketones (In the latter case) to give high yields of... 

Ring Expansion. The condensation of aldehydes and ketones with diphenylsulfonium cyclopropylide produces oxaspiropen-tanes which undergo ring expansion to produce cyclobutanones upon treatment with lithium perchlorate. ... 

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