This paper reports a novel synthetic method for the preparation of various urethanes and the application to the synthesis of carisbamate. The reaction of primary (2a, 2e and 2f) or secondary (2g-2i) trimethylsilyl ethers with chlorosulfonyl isocyanate afforded the corresponding urethanes in good yields without affecting the olefin moiety. However, in the case of secondary benzylic trimethylsilyl ether 2j, the corresponding urethane 3j was obtained in low yield. From the difference in reactivity between the primary and secondary benzylic trimethylsilyl ethers, the one-pot synthesis of carisbamate 1 from bis-trimethylsilyl ether 2l was achieved.
We report the concise synthesis of (+)-polyoxamic acid and (+)-5-O-carbamoyl polyoxamic acid from L-xylose in seven or six steps, respectively. The key steps include a diastereoselective amination of syn-1,2-polybenzyl ethers using chlorosulfonyl isocyanate (CSI) and the one-pot introduction of carbamates into the allylic benzyl ether and primary hydroxyl moieties.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.