Multivalent activation in temporary phosphate tethers: a new tether for small molecule synthesis.

[reaction: see text]. A new tether for small molecule synthesis is reported. This functionally active tether mediates the desymmetrization of a pseudo-C(2)-symmetric tris-allylic phosphate triester to generate a P-chiral bicyclo[4.3.1]phosphate containing ample steric and stereoelectronic differentiation for investigating chemo-, regio-, and stereoselective transformations. Overall, the method reported herein demonstrates a fundamentally new role of phosphates in synthesis and provides differentiated polyol building blocks for use in natural product synthesis.