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Ring-opening reactions of oxetanes yield important functionalized products depending upon the nature of nucleophiles as well as substitution pattern on the oxetane ring. Ring opening of oxetanes can be carried out under a variety of reaction conditions. In this review article, an up-to-date overview of major synthetic methodologies involved in the ring opening of oxetanes as well as their synthetic applications has been presented. [ABSTRACT FROM AUTHOR]

Epoxides bearing aryl groups function as “kick-starters” to markedly accelerate the photoinitiated cationic ring-opening polymerization of oxetane monomers. Thus, it has been observed that the inclusion of a small amount of styrene oxide transforms a sluggishly polymerizing 3-mono- or 3,3-disubstituted oxetane monomer into one that undergoes rapid, exothermic polymerization. Mechanistic studies suggest that the activity of aryl epoxides as “kick-starters” is related to their ability to intercept photogenerated acids to form benzylic cations that rapidly initiate oxetane monomer polymerization by alkylation of the monomer. [ABSTRACT FROM PUBLISHER]

Oxetane δ-amino acids were investigated as scaffolds to generate oxetane-based libraries. As pharmacophores, oxadiazoles and triazoles were built up on the scaffolds. Important physicochemical properties of target compounds were predicted in silico, and some physicochemical (solubility, logD, pKa values, permeation through artificial membranes) and metabolic (intrinsic clearance) properties were determined experimentally. The compounds synthesized exhibited the desired ADMETox properties. From an in silico point of view, this work adds valuable information for the refinement of prediction tools. [ABSTRACT FROM PUBLISHER]

Starting from d-xylose, 2,4-anhydro-5-N-(tert-butoxycarbonyl)amino-5-deoxy-3-fluoro-d-arabinonic acid 11 was synthesized over 10 steps including ring contraction, fluorination, and ester hydrolysis. Bromine oxidation of d-xylose followed by benzylidenation in a one-pot procedure led to a ca. 1:1 mixture of lactone 3 and 2,4;3,5-dibenzylidene xylonic acid (4) as by-product. For the synthesis of the d-xylo derivative 24, the chosen starting material was 1,2-O-isopropylidene-α-d-xylofuranose. A total of 14 steps including epimerization, ring contraction, fluorination, and saponification led to the desired fluoro-oxetane δ-amino acid 24. Hydrolysis of the 3-fluoro-oxetane δ-amino esters 10 and 23 by means of LiOH was successful in agreement with the results previously reported for similar 3-methoxy oxetanes, whereas chemical hydrolysis was not possible for 3-hydroxy derivatives. [ABSTRACT FROM AUTHOR]

Starting from 1,2-isopropylidene-d-xylose (1), 3-methoxyoxetane δ-amino acids with d-lyxo, d-ribo, and d-arabino configurations were synthesized. The early introduction of an azide function at C-5 of 1 shortened the synthetic pathway. Ring contraction of the intermediate d-xylono-1,4-lactone 6 via triflation and treatment with base led to the corresponding 3-methoxyoxetane δ-amino ester with d-lyxo configuration 7. The analogous procedure for d-ribono-1,4-lactone 16 furnished a mixture of d-ribo and d-arabino esters 17 and 18. Hydrolysis of the methyl esters 7, 17, and 18 to their corresponding δ-amino acids was successful with LiOH in THF, in contrast to that of their 3-hydroxy analog 11. [ABSTRACT FROM AUTHOR]

Starting from 1,2‐ O ‐isopropylidene‐D‐xylose, methyl 2,4‐anhydro‐3,5‐di‐ O ‐benzyl‐D‐lyxonate (4) was synthesized. Debenzylation and transformation of the primary hydroxyl group yielded methyl 2,4‐anhydro‐5‐ N ‐( t ‐butoxycarbonyl)amino‐D‐lyxonate (9). While transesterification of 4 under basic reaction conditions was straightforward, an analogous reaction with 9 was not successful. After screening of several lipases, the enzymatic transesterification of 9 was achieved with lipase L2 from Candida antarctica to furnish the title compound 2,4‐anhydro‐5‐ N ‐( t ‐butoxycarbonyl)amino‐D‐lyxonic acid in excellent yield. The stereochemistry at the oxetane ring was proven by an x‐ray structure of the intermediate methyl 2,4‐anhydro‐5‐azido‐D‐lyxonate. [ABSTRACT FROM AUTHOR]