[3+2] Cycloaddition-mediated synthesis of 3-methylsulfanyl-pyrrolidine-3-carboxylic acid methyl ester

1,3-Dipolar cycloaddition reactions are fundamental processes in organic chemistry. Herein we report [3+2] annulation of thiomethylacrylate 2 and azomethine ylide precursor 3 towards the synthesis of novel 3-methylsulfanyl-pyrrolidine 5. Alternatively, we have also explored the alkylation of 7 with dimethyldisulfide/LDA for the introduction of thiomethyl group towards the synthesis of 5 in moderate to good yields. Efficacy of these two routes under various conditions/catalysts for the synthesis of 5 is presented.