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Updated: Aug 23, 2026
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Solid-phase Synthesis of [4.4] Spirocyclic Oximes
Published on: February 6, 2019
Stereoselectivity in formation of oxacephams from 1,3-alkylidene-threitols
Katarzyna Borsuk1, Barbara Grzeszczyk, Patrycja Szczukiewicz
1Institute of Organic Chemistry of the Polish Academy of Sciences, Warsaw, Poland.
Abstract:
The [2+2]cycloaddition of CSI to the (Z)-propenyl ethers derived from respective 1,3-methylidene- and 1,3-ethylidene-threitols, contrary to the corresponding erythritol derivatives, is characterized by a low stereoselectivity and a lack of stereospecificity. On the other hand, the alternative method of the oxacepham formation, based on the 4-vinyloxy-azetidinone, proceeds with an excellent stereoselectivity. The CD-spectroscopy offers an attractive tool for determination of the absolute configuration of the bridgehead carbon atom at the 5-oxacepham skeleton.
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