Furanoid and Pyrrolidine Compounds

33 Furanoid (and Pyrrolidine) Compounds. - For making 2,3,5-tri-O-ben-zoyl-p-D-ribofuranosyl cyanide it is reported to be better to use KCN rather than 

Treatment of l,2-0-isopropylidene-3,5-di-0-mesyl-6-0-trityl-D-glu-cose with ethanediol and TsOH gives the C-formyl compound 161 in 53% yield from which (+)-muscarine iodide 162 and its epimer at the alcohol centre were made. Compounds 163 and 164 have been made from 2-deoxy-D-ribose donors by reaction with a benzyl Grignard reagent and allyltrimethylsilane, respectively, in the key steps. The products were incorporated into oligonucleotides during a study of the interactions of DNA with peptides.  

A long paper has appeared on synthetic and conformational studies of compound 165 (and its epimers at C-2 and C-5), made from 6-azido-2,3,4-tri-0-benzyl-6-deoxy-D-glucitol. These were amide linked to amino-acids at both C-1 andC-6.323 

Condensation of the corresponding aldonolactone derivative with 1,1,1-tri-chlorotoluene and trimethyl phosphite gives the exo-alkenes 166 from which C-glycosides are available. Reaction of 0-substituted 1,2-0-isopropylidene-a-D-xylofuranose with allyltrimethylsilane and a Lewis add gives the 2-0-un-protected p-C-allyl C-glycosides.  

0-Protected methyl 2-deoxy-D-ribofuranosides have been condensed with o-disubstituted benzenes to give compounds 172 (X,Y = OH, NH2) for incorporation into DNA which permits base-pairing by means other than H-bonding. For example, borate anion coupling was examined.  

---