(1aS,5aR)-1,1,2-trimethyl-1,1a,5,5a-tetrahydro-3-thia-cyclopropa[a]pentalene-4-carboxylic acid → (1aS,5aR)-1-(1,1,2-Trimethyl-1,1a,5,5a-tetrahydro-3-thia-cyclopropa[a]pentalen-4-yl)-ethanone

Participants

Reaction Steps

To a solution of (1aS,5aR)-1,1,2-trimethyl-1,1a,5,5a-tetrahydro-3-thia-cyclopropa[a]pentalene-4-carboxylic acid (220 mg, 1.00 mmol) in Et2O (10 mL) is added a solution of MeLi (1.6 M, 1.4 mL, 2.10 mmol) in Et2O at such a pace that the reaction mixture is refluxing gently. Upon completion of the addition, stirring is continued at rt for 30 min. The reaction is quenched by adding sat. aq. NH4Cl (3 mL). The organic layer is separated, dried over Na2SO4 and the solvent is evaporated to give (1aS,5aR)-1-(1,1,2-trimethyl-1,1a,5,5a-tetrahydro-3-thia-cyclopropa[a]pentalen-4-yl)-ethanone (165 mg) as a pale yellow oil; LC-MS: tR=1.03 min, [M+1]+=221.20; 1H NMR (CDCl3): δ 3.00 (ddd, J=1.8, 4.7, 18.8 Hz, 1H), 2.80 (d, J=18.8 Hz, 1H), 2.38 (s, 6H), 1.93-1.90 (m, 2H), 1.14 (s, 3H), 0.74 (s, 3H).

Provenance & Evidence