203397-92-6Relevant articles and documents
Aminolysis of vinyl epoxides as an efficient entry to N-H vinylaziridines
Lindstroem, Ulf M.,Somfai, Peter
, p. 109 - 117 (2007/10/03)
Vinyl epoxides 8a-f 11 and 12 have been prepared from the corresponding epoxy alcohols while 8g was formed by a regioselective epoxidation of the parent diene. Aminolysis of these materials resulted in a regio- and stereoselective nucleophilic opening at C3 in good yields except for the sterically hindered substrates. The trans-oxiranes gave the anti-amino alcohols while the cis derivative 12 gave the syn isomer 17. Cyclization of the anti-amino alcohols was best effected using the Mitsunobu protocol giving the corresponding N-H vinylaziridines in 50-54% yields, while the syn-amino alcohol 17 was transformed into the cis-vinylaziridine 31 with chlorosulfonic acid followed by base treatment in 20% yield. The outcome of these cyclizations seems to indicate that they are controlled by subtle steric effects in the substrate. The N-H vinylaziridine 24 was alkylated with tert-butyl bromoacetate and the product subjected to an aza[2,3]-Wittig rearrangement to give tetrahydropyridine 30 while acetylation of 24 followed by base treatment resulted in an aza-[3,3]-Claisen rearrangement yielding the seven-membered lactam 32.
