A FACILE METHOD FOR THE Α-Methylenation OF SULFONES

Abstract

The carbanion of α-monosubstituted β-benzoylsulfones reacted with formaldehyde under mild conditions to afford α-methylenated products (α-alkylated vinylsulfones) in high yield with the elimination of a benzoate anion.

Nucleophilic Vinylic Substitutions of (Z)-(β-Haloalkenyl)phenyliodonium Salts with Sodium Benzenesulfinate: First Evidence of a Michael Addition of Nucleophiles to Alkenyliodonium Salts at the Cβ Atom

“…Irradiation of the allylic protons in ( Z )- 5b , c resulted in 8−9% enhancements in the vinylic proton integration whereas only 2−3% enhancements were observed with ( E )- 5b , c , which is in good agreement with their assigned stereochemistry. The observed chemical shifts of vinylic protons in 5 support their stereochemical assignments: vinylic proton signals of ( Z )- 5b , c appeared at δ 6.76 whereas those of ( E )- 5b , c appeared at δ 7.38 . The structure of ( E )- 5b was established by a single-crystal X-ray analysis 22 (see Supporting Information).…”

“…( Z )-1,2-Bis(benzenesulfonyl)-1-propene (5a): colorless needles; mp 113−115 °C (recrystallized from dichloromethane-hexane) (lit 13a. mp 113−114.5 °C); IR (KBr) 3007, 1583, 1447, 1323, 1163, 1084, 723, 690 cm -1 ; 1 H NMR (CDCl 3 ) δ 8.11−8.03 (m, 4H), 7.74−7.54 (m, 6H), 6.82 (q, J = 1.3 Hz, 1H), 2.12 (d, J = 1.3 Hz, 3H); MS m / z (relative intensity) 322 (2, M + ), 258 (5), 218 (66), 141 (51), 125 (100), 77 (98).…”