New bi:cyclic oxazolidinone carbohydrate derivs. - useful in selective synthesis of diastereomers of chiral N-acyl analogues

摘要

Bicyclic oxazolidinone derivs. of formula (I), derived from carbohydrates, are new. In (I) R2 and R2 together complete a carbohydrate ring, in which the OH gps. are protected by acyl (e.g. propionyl, isobutyryl, pivaloyl, other 2-18C alkylcarbonyl or benzoyl) or by alkyl (e.g. Me, allyl). Also new are the acyl cpds. of formula (II). In (II) R1 and R2 are as above, but OH can also be protected by acetyl, R = (un)branched alkyl which may include functional gps., double and/or triple bonds. (I) are pref. derived from D-glucosamine or D-galactosamine and the OH protecting gp. is pivaloyl (Piv). USE/ADVANTAGE - (I) and (II) are useful in diastereoselective synthesis of cpds. (III) similar to (II) but with at least one chiral centre in R. They provide very high degrees (e.g. 90:10 or better) of selectivity. (I) can be produced efficiently from inexpensive carbohydrates.