this invention provides a practical synthesis route for 4 , 5 - dihydroxypentane - 2 , 3 - dione , an unstable small molecule which is proposed to be the source of universal signaling agents for quorum sensing in bacteria . the synthesis route includes new intermediates and allows preparation of isotopically - labeled dpd and ent - dpd . the method provides sufficient quantities of dpd for study of spontaneous binding of borate to dpd , the signal for the marine bacteria v . harveyi