Tandem inter [4+ 2]/intra [3+ 2] nitroalkene cycloadditions. 4. Cycloadditions with (E)-and (Z)-1-propenyl ethers

SE Denmark, CBW Senanayake

Index: Denmark, Scott E.; Senanayake, C. B. W. Journal of Organic Chemistry, 1993 , vol. 58, # 7 p. 1853 - 1858

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Citation Number: 54

Abstract

The tandem [4+ 21/13+ 21 cycloaddition of nitroalkene 1 was initiated efficiently by 1- propenyl ethers as the dienophile. Ethyl (E)-1-propenyl ether reacted highly selectively to give a single nitroso acetal cycloadduct 6. Hydrogenolysis of 6 afforded a single isomer of a- hydroxy lactam 8 wherein the newly installed methyl group occupied the@-configuration. Similarly, ethyl (2)-1-propenyl ether produced an anomeric mixture of cycloadducta 7a ...