A New Preparative Synthesis of 1-D-6-O-(2-Amino-2-Deoxy-D-glycopyranosyl)-chiro-Inositol 1-Phosphate and 1,2-Cyclic Phosphate

Abstract

A convenient preparative synthesis of 1‐D‐6‐O‐(2‐amino‐2‐deoxy‐α‐D‐glycopyranosyl)‐chiro‐inositol 1‐phosphate (III) and ‐1,2‐cyclic phosphate (IV) using D‐chiro‐inositol as starting material is reported. Compound III has been previously found to behave as type P inositolphosphoglycans (the putative second messengers of insulin‐like growth factor I) in organotypic cultures of chicken embryo. The synthesis of III and IV, now reported, considerably improves previous synthesis of III and permits the effective preparation of these substances for biological investigation.

A Study on the Influence of the Structure of the Glycosyl Acceptors on the Stereochemistry of the Glycosylation Reactions with 2‐Azido‐2‐Deoxy‐Hexopyranosyl Trichloroacetimidates

“…The results—which should be taken only as a qualitative indication of stereochemical outcome of these reactions as all experiments have been performed on a preparative basis and the yields calculated based on weight of isolated products—are summarized in Table 1 which also shows the results previously obtained for 5 11c. Although in general terms, the poor selectivity of the process in the D series was also observed in the L series, the results were indicative of a higher α selectivity in the case of the L ‐enantiomers.…”

“…The glycosylation of 9 with glycosyl donors 12 – 14 (Figure 4) was studied under the same experimental conditions as used before for the glycosylation of the D ‐enantiomer 5 11c. These experimental conditions had been previously established, from a preparative point of view, to obtain the α pseudodisaccharides 15 α, 17 α and 19 α as the main products from each of the glycosyl donors investigated…”

“…The stereoselectivity of these glycosylations also seemed to be somehow dependent on the structure of the acceptor. In the case of the D ‐ chiro ‐inositol derivatives, where a series of pseudodisaccharides were required having the α1→1 glycosidic linkage, the reaction of acceptors 5 , 6 and 7 with 2‐azido‐2‐deoxy‐ D ‐glucopyranosyl trichloroacetimidates, afforded anomeric mixtures containing a considerable amount of the β‐anomers 11c,g,h. By contrast, the α1→2 glycosidic linkage in the same D ‐ chiro series and the α1→3 glycosidic linkage in the L ‐ chiro series11i as well as the α1→6 glycosidic linkage in the D ‐ myo series11b,e were formed with fair to good stereoselectivity under similar experimental conditions.…”

Synthesis of New Hexosaminyl D‐ and L‐chiro‐Inositols Related to Putative Insulin Mediators

“…The methyl ether group of L ‐quebrachitol was cleaved as previously reported9 to give L ‐ chiro ‐inositol. Treatment of L ‐ chiro ‐inositol with the bifunctional protecting agent 1,3‐dichoro‐1,1,3,3‐tetraisopropyldisiloxane (TIPDSCl 2 ) under carefully controlled experimental conditions1c gave a mixture of silylated derivatives that was directly submitted to conventional benzoylation to give compounds 1a (36%), 1b (22%), and 1c (15%). Removal of the silyl protecting group in 1a afforded diol 2 in 90% yield.…”

Synthesis of galactosaminyl d-chiro-inositols

“…While several differentially protected 8 chiro-inositols have been synthesized, [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] we sought a general strategy for the syntheses of a complete set of penta-O-benzyl-D D-chiro-inositols, each with a different unprotected hydroxyl group for glycosylation. Since chiro-inositol has a C 2 axis of symmetry, the set consists of only three different penta-O-benzyl-chiro-inositols: 8, 9, and 10.…”