ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 43, Number 3
JKCSEZ 43(3)
June 20, 1999 

Geminal bisphosphonates have been well known to be effective inhibitors of various calciumrelated disorders such as Paget's disease, hypercalcemia of malignancy, and osteoporosis. To synthesize bisphosphonates, we have used the pentacovalent oxaphospholene prepared from methyl vinyl ketone and triethyl-phosphite. Υ-Ketobisphosphonates are obtained by bromination, applied Westheimer reaction, and hydrolysis of synthesized oxaphospholene. This compound was converted to the N-alkylated Υ-aminobisphosphonates by the reductive amination. Conversion of the resulting secondary amine to the tertiary one, followed by introduction of the second alkyl group on the nitrogen, was led to the synthesis of new N,N'-dialkylated Υ-aminobisphosphonates.