Deoxy Xylo-hexofuranose

The mass spectra of methyl 3-deoxy-p-v-tkreo-pentopyrano-side, methyl 4-deoxy-j3-T>-thieo-pentopyranoside, and 5-deoxy-fi-D-xylo-furanoside are discussed and compared fragmentation paths are sufficiently different to allow identification on the basis of their mass spectra. On the other hand, the mass spectra of methyl 2- and 3-deoxy-5-O-methyl-f3-i>-erythro-pentofuranosides do not exhibit fragmentation differences. The mass spectra of 3-deoxy-l,2 5,6-di-O-isopropylidene -d-xylo - hexofuranose, 5- deoxy -1,2-0-isopropylidene-D-xy o-hexofuranose, and 6-deoxy-l,2-0-iso-propylidene-D-glucofuranose show prominent differences, even between the 5- and 6-deoxy isomers. The interpretation of the spectra was aided by metastable-ion peaks, mass spectra of DzO-exchanged analogs, and the mass spectrum of an O-isopropylidene derivative prepared with acetone-d6. 

Cyclohexan 2-Oxo-l,l,3,3-tetrakis-[hydroxymethyl]- VII/2b, 1462 6-Deoxy-a-D-galactopyranosid Methyl-3,4-O-isopropyliden-E19a, 153 (6-1 -> H) 5-Deoxy-a-D-xylo-hexofuranose ... 

O-isopropylidene-a-D-xylo-hexofuranose and 6-deoxy-l, 2-O-iso-propylidene-)8-L-idofuranose in 62 and 30% yield, respectively. Various conditions were tested, " without success, for raising the yield of 5-deoxy-l,2-0-isopropylidene-a-D-xt/io-hexofuranose the yield was significantly lowered (about 30%) when the hydride reduction was performed in tetrahydrofuran. A mechanism was proposed for formation of the two products namely, that formation of 6-deoxy-... 

Tetra-Ac 1,2,5,6-Tetra-0-acetyl-3-deoxy-D-xylo-hexofuranose [23655-60-9]... 

Following Bock s observation with the only substrate that had been converted quantitatively, 5-deoxy-D-xylo-hexofuranose ( 5-deoxy-D-glucose , 59), it was discovered [83] that any derivative of D-glucose not bearing a free hydroxyl function at C-5, such as the 5-azidodeoxy (71), the 5-deoxyfluoro (73), and the 5-0-... 

The addition of iodine trifluoroacetate (produced by reaction of iodine with silver trifluoroacetate) to unsaturated carbohydrates has been investigated.134 Treatment of 5,6-dideoxy-l,2-0-isopropylidene-a-D-xylo-hex-5-enofuranose (89) with silver trifluoroacetate and iodine in acetonitrile gave 3,6-anhydro-5-deoxy-5-iodo-l,2-0-iso-propylidene-a-D-gluco(and /3-L-ido)furanose (91) and 5-deoxy-5-iodo-l,2-0-isopropylidene-6-0-(trifluoroacetyl)-o -D-gluco(and/or /3-L-ido)-furanose (92), with the former preponderating. Component 91 was converted into 3,6-anhydro-5-deoxy-l,2-0-isopropylidene-a-D-xj/io-hexofuranose (94) by hydrogenation over Raney nickel (see also, Section III,3 p. 299), and component 92 was converted into 5-deoxy-l,2-0-isopropylidene-a-D-xy/o-hexofuranose (95) by treat-... 

Hexofuranose, 3,6-anhydro-5-deoxy-l,2-O-isopropylidene-a-D-xylo-, 241 —, 5 - deoxy -1,2 - O - isopropylidene - a - D -xylo-, 275... 

---