Selective hydroxyl protection of (+)-noviose via improved synthesis

Coumarin antibiotics are biologically important molecules embedded with (+)-noviose as signature moiety. A challenging problem concerning the synthesis of these molecules and their analogues is the difficulty in selective protection of the two non-anomeric OHs of (+)-noviose. In order to provide a useful solution to this problem, we report here a new strategy of (+)-noviose synthesis, modified from Musicki’s previous study. Dihydrofuranone 8 was thus prepared from l-arabinose and was employed as key intermediate to provide previously unknown 3-O-BOM-Noviose 9 in seven steps (40% overall yield). Compound 9 was then efficiently converted into noviose 1,2-acetonide 6 (66%, two steps), which was otherwise only available from controlled degradation of naturally occurring novobiocin 1.