(3R,4S)-3,4,5-Trihydroxy-4-methylpentylphosphonic acid, an isosteric phosphonate analogue of 2-C-methyl-d-erythritol 4-phosphate, a key intermediate in the new pathway for isoprenoid biosynthesis

2-C-Methyl-d-erythritol 4-phosphate (MEP) is the first intermediate in the mevalonate-independent pathway for isoprenoid biosynthesis presenting the branched C5 isoprene skeleton. Enantiopure (3R,4S)-3,4,5-trihydroxy-4-methylpentylphosphonic acid (MEPN), an isosteric phosphonate analogue of MEP was synthesized from 1,2-O-isopropylidene-α-d-xylofuranose.