| Title | Regioselectivity of alkylation of cyclomaltoheptaose ([beta]-cyclodextrin) and synthesis of its mono-2-O-methyl, -ethyl, -allyl, and -propyl derivatives |
| Publication Type | Journal Article |
| Year of Publication | 1995 |
| Authors | Jindřich J, Pitha J, Lindberg B, Seffers P, Harata K |
| Journal | Carbohydrate Research |
| Volume | 266 |
| Issue | 1 |
| Pagination | 75 - 80 |
| Date Published | 1995/01/03/ |
| ISBN Number | 0008-6215 |
| Keywords | Cyclodextrin, Cyclomaltoheptaose ([beta]-cyclodextrin), derivatives of, duplicate, Synthesis, [beta]- (cyclomaltoheptaose) |
| Abstract | Mono-2-O-methyl-, -2-O-ethyl-, and -2-O-allyl-cyclomaltoheptaose were prepared by alkylations of cyclomaltoheptaose in dilute aqueous alkali, and mono-2-O-propylcyclomaltoheptaose was obtained by hydrogenation of the allyl derivative. All the 2-O-alkyl derivatives were less soluble in water than was cyclomaltoheptaose. All formed inclusion complexes with toluene in aqueous solution, but only the methyl ether was less soluble in the water-toluene system than in water. The solubilities of the other ethers in water were enhanced by the addition of toluene. Partial methylation of cyclomaltoheptaose with 13C-enriched dimethyl sulfate in dilute aqueous alkali yielded mixtures of products. The substitution patterns were analyzed by GLC-MS of the alditol acetates, prepared by hydrolysis, reduction, and acetylation, and by 13C NMR after complete permethylation with nonenriched reagent. The results showed that methylation at O-2 is a predominant but not an exclusive reaction; as expected, the regioselectivity decreases with increasing degree of methylation. |
| URL | http://www.sciencedirect.com/science/article/B6TFF-3YF4G1X-7/2/690d5325a9157e3ed722b6f4ae385411 |
