THE PREPARATION OF SOME BROMODEOXY- AND DIBROMODIDEOXY-PENTONOLACTONES

Article abstract of DOI:10.1016/S0008-6215(00)82222-3

Treatment of ammonium D-xylonate with hydrogen bromide in acetic acid yields 2,5-dibromo-2,5-dideoxy-D-lyxono-1,4-lactone (2a), whereas similar treatment of potassium D-arabinonate gives 5-bromo-5-deoxy-D-arabinono-1,4-lactone (8a) as the main product.Two isomeric 2,5-dibromo-2,5-dideoxy-1,4-lactones are also formed in minor amounts.Selective hydrogenolysis of 2a affords 5-bromo-2,5-dideoxy-D-threo-pentono-1,4-lactone, while prolonged treatment results in the formation of 3-hydroxypentanoic acid.Similarly, hydrogenolysis of 8a produces a 2,3-dihydroxypentanoic acid together with smaller amounts of 5-deoxy-D-arabinono-1,4-lactone; the latter also results from hydrogenolysis of 5-deoxy-5-iodo-D-arabinono-1,4-lactone with Raney nickel.