Sulfones, bis-propargylic

Kerwin, S. M., (1994) Synthesis of a DNA-cleaving bis(propargylic) sulfone crown ether Tetrahedron Lett. 35, 1023-1026. 

An alternative use was found for bis-propargylic sulfones by Nicolaou et al., who hypothesized that such systems may be DNA-cleaving agents through their ability to form... 

Scheme 7-35 Synthesis of the parent carbocycle 150 of the NCS chromophore by photolytic ring contraction of the bis-propargylic sulfone 148 (Wender et al.).

Garratt—Braverman cyclization (base-mediated rearrangement of bis-propargyl sulfones via bis-aUenes generated in situ), a powerful tool for C—C bond formation 12SL2582. 

Reaction of alkynol 401 with sulfur dichloride leads to alkynyl sulfmyl ester 402, which, when heated, rearranges to bisallenyl sulfone 403. Pyrolysis of 403 yields thiophene 1,1-dioxide 404 (Scheme 66) <1996LA171>. The reaction of bis-propargylic derivatives 405 with l,8-diazabicyclo[5.4.0]undec-7-ene (DBU) leads to dihydrobenzothiophenes 407 via a tandem cyclization of the intermediates 406 (Scheme 67) <2000TL2675, 2005JOC10166>. 

Diallenylsulfone (76) and the thiophene dioxide (77) are intermediates in the base-catalysed conversion of bis(y-alkenylpropargyl)sulfones (75) to the corresponding dihydrothiophene dioxides (78). The slowest step in the multistep process is the propargyl to allenyl tautomerization.181... 

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