Imino sugars pyrrolidine

Doddi and Vankar have described efficient syntheses of two pyrrolidine-based imino sugars, 431 and 432, beginning from the MBH adduct of (R)-2, 3-0-isopropylideneglyceraldehydes. The key steps included regiospecific amination via successive S n2 --S n2 displacement reactions), RCM and diastereospecific dihydroxylations (Scheme 3.192). These azasugars were reported to be moderate inhibitors of glycosidase. ... 

Vankar s group reported the synthesis of a novel family of bicyclic imino sugars, which can be regarded as conformationally locked pyrrolidines (Scheme 1). Syn-dihydrojylation of n-glucal-derived compound 1 gave diol 2 as an inseparable mixture of isomers (dr=3 2). After tritylation, both diastereoisomers (3 and 4) were easily separated by chromatography and the major diastereoisomer 3 was converted into the bicyclic imino sugar 6... 

Carbohydrates continue to provide efficient precursors of functionalized pyrrolidines. The 2,3-disubstituted pyrrolidine 142 (sugar numbering shown), a precursor to the pyrrolidizidine class of alkaloids, has been prepared from D-galactose and the 3,6-imino-derivative 143 (from D-glucose) has been utilized in the synthesis of (-)-detoxin Dj 144 and (+)-valydetoxinine 145 (see Vol. 26, p.313) Jouille has also published a review of synthetic work carried out in the detoxin field, some of which is carbohydrate based. ... 

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