Welwitindolinone alkaloids

Three new chlorinated welwitindolinone alkaloids, e.g. 218, have been isolated from the terrestrial cyanophytes Fischerella muscicola and Fischerella major [169]. 

Welwitindolinone A isonitrile (271) [108], one of several related oxindole-con-taining alkaloids, such as hapalindole (272) [109, 110], fischerindole (273) [108], and ambiguine H (274) [111, 112], was isolated from blue-green algae by Moore... 

Stratmann K, Moore RE, Bonjouklian R, Deeter JB, Patterson GML, Shaffer S, Smith CD, Smitka TA (1994) Welwitindolinones, unusual alkaloids from the blue-green algae Hapalosiphon welwitschii and westiella intricata. Relationship to fischerindoles and hapa-lindoles. J Am Chem Soc 116 9935-9942... 

The [5-hi] cycloaddition of allenylcyclopropane and CO has been successfully employed to synthesize the cyclohexenone core of indole alkaloid welwitindolinones by Zhang and Tang [20]. Starting from commercially available 4-cyanoindole 103, cyclopropane intermediate 105 was obtained through intramolecular cyclopropanation of alkenes with chlorodiazoaceate 104. Then allenylcyclopropane 106,... 

Stratmann, K., Moore, R.E., Bonjouklian, R., Deeter, J.B., Patterson, G. M., Shaffer, S., Smith, C.D., and Smitka, TA. (1994) Welwitindolinones, imusual alkaloids from the blue-green algae Hapalosiphon wdwitschii and Westiella intricata. Relationship to fisherindoles and hapalindoles./. Am. Chem. Soc., 116, 9935-9942. 

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