Facile synthesis of spiroisoquinolines based on photocycloaddition of isoquinoline-1,3,4-trione with oxazoles

Abstract

Photocycloaddition of isoquinoline-1,3,4-trione and 5-methoxyoxazoles affords spiroisoquinolineoxetanes with high regio- and diastereoselectivity. The spiroisoquinolineoxetanes can be conveniently converted into novel spiroisoquinolineoxazoline derivatives through acid catalyzed sequential reactions.

(1S*,4′S*,5R*)-1-Isopropyl-5-methoxy-2′,3-dimethyl-4,6-dioxa-2-azaspiro[bicyclo[3.2.0]hept-2-ene-7,4′-isoquinoline]-1′,3′(2′H,4′H)-dione

“…For general background to and the potential biological activity of the title compound, see: Pollers-Wieers et al (1981); Malamas et al (1994); Yu et al (2010); Du et al (2008); ; Zhang et al (2006); Mitchell et al (1995Mitchell et al ( , 2000; Harris et al (2005); Wang et al (2010); Huang et al (2011). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).…”

“…Since a lot of natural products especially the alkaloids containing the isoquinoline or oxazole ring are bioactive, there has been intense development of methodology to construct such moieties (Wang et al, 2010). The title compound which was derived from isoquinoline-1,3,4-trione and oxazoles (Huang et al, 2011) may have potential use in biochemical and pharmaceutical fields. Due to the importance of the isoquinoline-1,3,4-trione derivatives, we report herein the crystal structure of the title compound with a relative configuration of (1S * , 4′S * , 5R * ).…”

(1S*,4′S*,5R*)-1-Isobutyl-5-methoxy-2′,3-dimethyl-4,6-dioxa-2-azaspiro[bicyclo[3.2.0]hept-2-ene-7,4′-isoquinoline]-1′,3′(2′H,4′H)-dione

“…Isoquinoline-1,3,4-trione and its derivatives have been reported to be redox mediators of photosystems I and have been used as herbicides (Mitchell et al, 2000;1995). The title compound which was derived from isoquinoline-1,3,4-trione and oxazoles (Huang et al, 2011) may have potential use in biochemical and pharmaceutical fields. We report herein the crystal structure of the title compound with a relative configuration of (1S * , 4′S * , 5R * ).…”

Recent Applications of Oxetanes in the Synthesis of Heterocyclic Compounds

“…30 Carreira developed a novel access to isoxazoles from a base mediated rearrangement of nitromethyleneoxetanes, generated in situ from nitroalkanes and oxetan-3-one. 31 Mechanistic studies provided evidence for the formation of highly strained oxetene intermediates that undergo ring opening with nitronate anions, and subsequent dehydration provides isoxazole aldehydes.…”