Synthesis of Alkyldibenzophosphole 5-Oxides.

The synthesis of 5-alkyl-5H-dibenzophosphole 5-oxides has been re-studied. Ethyl-, dodecenyl- and heptadecyldibenzophosphole oxides have been synthesised by the alkylation of the P-methylide generated by lithiation of 5-methyl-5H-dibenzophosphole 5-oxide. An improved method for the synthesis of the latter oxide is also described.