Efficient Synthesis of a Novel Estrone- Talaromycin Hybrid Natural Product

Abstract

Numerous pharmacologically interesting compounds are available by the synthesis of hybrid natural products. Thus, for instance, the estrone-talaromycin hybrid 2, which is synthesized in a few steps from the estrone derivative 1 by a sequence in which a hetero-Diels-Alder reaction is the key step, exhibits notable cytotoxic activity.

1-[2-Oxo-1′-phenyl-2′,3′,5′,6′,7′,7a'-hexahydroindoline-3-spiro-3′-1′H-pyrrolizin-2′-yl]-3-phenylprop-2-en-1-one

“…For related literature, see: Araki et al (2002); Caine (1993); Gore et al (1991); Harris & Uhle (1960); Ho et al (1986); James et al (1991); Kobayashi et al (1991); Ramesh et al (2007); Stevenson et al (2000); Tietze et al (1988). For ring puckering parameters, see: Cremer & Pople (1975).…”

“…Spiro-compounds are a particular class of naturally occurring substances characterized by highly pronounced biological properties (Kobayashi et al, 1991;James et al, 1991). The spiro-pyrrolidine ring system is also found in phermones, antibiotics (Gore et al, 1991) and antitumour agents (Tietze et al, 1988;Araki et al, 2002). Indole compounds can be used as bioactive drugs (Stevenson et al, 2000).…”

Heterogeneous Catalytic Enantioselective Hydrogenation of Activated Ketones

“…Studies on enantioselective catalytic hydrogenation at the University of Szeged started with the investigation of the MRNi catalyst [247][248][249][250]. These studies were also extended to the hydrogenation of steroids [251][252][253][254][255][256][257][258], an important family of compounds successfully researched at the University of Szeged [259][260][261][262]. Finally, last year a new project was launched to study the enantio-and diastereoselective hydrogenation of certain other compounds containing prochiral C=C bonds [263][264][265].…”

4′-(4-Methylbenzoyl)-1′-methyldispiro[indole-3(2H),2′-pyrrolidine-3′,3′′(2′′H)-indole]-2,2′′-dione

“…The spiro-pyrrolidine ring system is a frequently encountered structural motif in many pharmacologically relevant alkaloids (Cordel, 1981). It is also found in phermones, antibiotics (Gore et al, 1991) and antitumour agents (Tietz or Tietze et al, 1988;Araki et al, 2002). Several optically active pyrrolidines have been used as intermediates in controlled asymmetric syntheses (Suzuki et al, 1994).…”