Phosphines hexa tertiary

As a final accomplishment, the reaction between (63) and the bis(electrophile) (70) afforded the 24-membered hexa(tertiary arsine) (71) in 15% yield. A 6% yield of (71) resulted from the reverse condensation, that is, the reaction of (66) with the bis(arsenide) (72) (Scheme 11). The product was isolated by column chromatography and characterized by elemental analysis and MS. The ease with which the heterocycles (64) and (69) and (71) can be purified by column chromatography is an important physical property that distinguishes them from similar tertiary phosphines and opens up the possibility for the complete separation of diastereomers. 

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