1,3,4-Oxa- und 1,3,4-Thia-diphospholane aus Diphosphorsubstituierten 2-Oxa- und 2-Thia-propanen

1,3,4-Oxadiphospholanes and 1,3,4-Thiadiphospholanes from Diphosphorus-substituted 2-Oxa- and 2-Thia-propanes The synthesis of phosphonates and phosphinates of the type (RO)₂(O)PCH₂ZCH₂P(O)(OR)₂, R¹(RO)(O)PCH₂ZCH₂P(O)(OR)₂ and R¹(RO)(O)PCH₂ZCH₂P(O)(OR)R¹ (with Z = O, S; R = Et, Prⁱ; R¹ = Me, Ph) is reported. Acyclic diphosphanes, R¹(H)PCH₂ZCH₂P(H)R² (with Z = O, S; R¹ = R² = H, Me, Ph; R¹ = H, R² = Me), and 1,3,4-Oxadiphospholanes as well as 1,3,4-Thiadiphospholanes are obtained from the esters by reduction.