Vinyl sulfones hydrogenolysis

Hydrogenolysis of vinyl sulfones.2 Vinyl sulfones are reduced by Na2S204 and NaHC03 in aqueous ethanol with retention of configuration. The reaction is facilitated by use of a phase-transfer catalyst such as Adogen. The reduction involves addition of HSOz to form a sulfone sulfinate salt which can be trapped by CH3I. The overall reaction thus involves a (3-syn-addition followed by an anti-elimination. This hydrolysis was used in a synthesis of several insect pheromones, such as (Z)-8-dodecenyl-l-acetate (1). 

Hydrogenolysis of vinyl sulfides,vinyl sulfoxides and vinyl sulfones is rare, and may be accompanied by saturation of the double bond. Thus vinylic sulfide (29) gives only 5% of l,5-diphenyl-2-... 

Julia M, Lauron H, Stacino JP, Verpeaux JN, Jeannin Y, Dromzee Y. Organic synthesis with sulfones. 38. On the mechanism of the stereospecific hydrogenolysis of vinylic sulfones by sodium dithionite. Tetrahedron 1986 42 (9) 2475-2484. 

---