Vincadifformine chloroindolenine

The base 358 is only one of four products obtained when vincadifformine chloroindolenine (295) is allowed to stand with aqueous acetic acid 243). The other products are the corresponding hydroxyindolenine 285 the pen-tacyclic base (362), identical with that obtained earlier by solvolysis of 295 with hot aqueous tetrahydrofuran 244) and a new tetracyclic base, formulated as 3. When heated in acetic anhydride, the chloroindolenine... 

Reaction of vindoline (3) with the chloroindolenines derived from vin-cadifformine (127a), iJ -vincadifformine (133), -tabersonine (133a), or synthetic pandoline (34) (7/5, 116), followed by reduction of the resulting imines 145 and 145a (Scheme 40) with potassium borohydride, had given... 

Le Men and co-workers have performed several studies of the chemistry of the chloroindolenine of tabersonine (320) (174,178). This compound is produced in high yield when tabersonine (28) is treated with a slight excess of tert-butyl hypochlorite in anhydrous methylene chloride at —16° in the presence of triethylamine (178). In order to demonstrate that no skeletal changes had occurred, they carried out reconversion to tabersonine with potassium ferf-butoxide in benzene under reflux. Similarly prepared was the chloroindolenine of vincadifformine. Subsequent reactions demonstrated that these chloroindolenines were highly reactive. 

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