tBuLi with 1-phenyl 3, 4-dimethyl phosphole sulfide 1 in THF, gives a mesomeric anion 4. With aldehydes and ketones, this anion leads to methyl-substituted phospholes (6 and 9), 2- substituted phospholes (8) or 2-substituted 3-methylene phosphol 4-enes (5 and 7). With CO2 and CH3COOEt a 2-phosphole carboxylic acid 11 and a 2-acetyl phosphole 10 are obtained, respectively. The spectra of the 2-substituted phospholes are studied in some ...
