The Determination of Primary Hydroxyl Groups in Cellulose Acetate by Tosylation and Iodination

Deoxycelluloses and related structures

“…As expected, a comparative study demonstrated that cellulose tosylate was a better leaving group than cellulose nitrate and that nucleophilic displacement to form halodeoxycelluloses increased in the order I b Br b Cl with optimum substitution occurring in solvents such as cyclohexanone rather than in aqueous solutions [5]. There are numerous earlier studies that describe the preparation of iododeoxycellulose by displacement of leaving groups such as tosylate [6] and later studies that describe its preparation by reaction of chlorodeoxycellulose with NaI in 2,5-hexanedione [7]. Since iodide ion is a good nucleophile and the methods for direct iodination of hydroxyl groups are somewhat limited, most iododeoxycelluloses reported in the literature have been made by a two step sequence with the latter step being displacement of a leaving group by iodide ion.…”

Cellulose carboxylate/tosylate mixed esters: Synthesis, properties and shaping into microspheres

“…As a results of the presence of different functionalities, their films can adsorb other material, e.g., biomacromolecules, by dipolar, hydrogen-bonding and van der Waals interactions. Although few Cel-Carboxy/Ts have been synthesized, the emphasis was on their further use to obtain the above-mentioned deoxy products (Heinze et al 1996a;Heinze et al 1996b;Malm et al 1948). Some of these mixed esters are readily soluble in dipolar aprotic solvents, e.g., DMSO (dimethylsulfoxide), DMAc (N,N-dimethylacetamide) and THF (tetrahydrofuran), and form films by casting from solution.…”

Bismethylenedioxy Steroids. IV.1 11α-Methylhydrocortisone Acetate and 9α-Chloro-11α-Methylhydrocortisone Acetate

“…Bromination and Dehydrobromination of 7pMethyl-17,20;20,21bismethylenedioxyallopregnane -3, 11 dione (XIVb).-The diketone (50 mg.) was dissolved in 1.5 ml. of dimethylformamide and to this solution was added 22.5 mg. of bromine in 1.5 ml.…”

“…1 1 a-Methylhydrocortisone Acetate.-Reaction of cortisone-BMD (I)* with ethylene glycol-p-toluenesulfonic acid gave cortisone-BMD-3-dioxolane (11). When I1 was allowed to react with excess methyl-lithium12 for four hours a t room temperature] a 60% yield of 11 a-methylhydrocortisone-BkID-3dioxolane (111) was isolated by direct crystallization.…”

“…;20,2 l-Bismethylenedioxy-4-pregnene-3,11 -dione (I).-Fifty grams of cortisone was suspended in 2000 ml. of chloroform.…”