90456-29-4Relevant academic research and scientific papers
A New Route to Cyclazines
Batroff, Volker,Flitsch, Wilhelm
, p. 621 - 628 (2007/10/02)
In search of routes to 5b,7a-dihydrocyclobutacyclazines 2, which should be starting materials for a photochemical synthesis of the diradicaloid cyclazine (1), cycloaddition reactions of indolizines 8 with electron-deficient olefins and acetylenes in the absence of dehydrogenating reagents have been studied.The tetracyclic compound 9 was obtained from 8b and 1-cyclobutene-1,2-dicarbonitrile.Upon oxidation 9 was rearranged to yield the cyclazine 10. - The cycloadducts 6a and b have been obtained from the reaction of dimethyl maleate with the indolizines 8b and c.The compounds 6a and b were transformed into the cyclic thioethers 22 on conventional routes.A Stevens rearrangement of 22b, intended to result in a ring contraction, gave the 3,5-divinyldihydroindolizine 24 in good yields.Cycloaddition reactions of dimethyl acetylenedicarboxylate and indolizines 8 yielded the cyclazine derivatives 3 and 4a-c.
ADDITION REACTION OF INDOLIZINE DERIVATIVES WITH DIMETHYL ACETYLENEDICARBOXYLATE
Yamashita, Yoshiro,Suzuki, Daisuke,Masumura, Mitsuo
, p. 705 - 708 (2007/10/02)
Indolizine derivatives 1 reacted with dimethyl acetylenedicarboxylate to give 1:1 adducts 2-6.In some cases 1:2 adducts 7 were obtained from which cyclazine derivatives 11 were synthesized by dehydrogenation.The addition reaction was dependent on t
