Thallium trinitrate synthesis

The synthesis13 of the pentacyclic intermediate (10) constitutes a second formal synthesis of ( )-tryptoquivaline G, since (10) has already been converted into tryptoquivaline G by Biichi et al.14a The most noteworthy stages in the synthesis of (10) (Scheme 1) involved the oxidation of the indolepropionic acid derivative (11) by means of thallium trinitrate, which gave the oxindole-lactone (12), and the oxidative removal of the unwanted methyl group in (12) by means of selenium dioxide.13... 

A facile synthesis of allenic esters (187) is by reaction between acid chlorides (185) and phosphoranes (186) derived from a-halo-esters. Yields are 10— 70% presumably ketens are intermediates. Cyclic /3-keto-esters can serve as precursors to cyclic allenic esters by sequential conversion to the 2-pyrazolin-5-one derivatives, using hydrazine and oxidation with thallium trinitrate (Scheme 26) overall yields are around 50%. ... 

Ferraz HMC, Silva LF Jr, Vieira TO. Thallium trinitrate-mediated ring contraction of 1,2-dihydronaphthalenes an approach to the synthesis of indans. Tetrahedron 2001 57 1709-1713. 

The first total synthesis of tryptoquivaline G (FTG) was achieved by Biichi et al. (158) (Scheme 15), which confirmed the proposed structure and established the relative and absolute configurations. Subsequently, Ban s group (159) effectively prepared Biichi s intermediate (90) through thallium(III) trinitrate (TTN) oxidation at a crucial step of spirolactonization. More recently, Hino s group achieved a short-step total synthesis of tryptoquivaline (160,161) and tryptoquivaline G (162) through oxidative double cyclization of the N-acyltryptophan precursor with A-iodosuccinimide (NIS) in CF3COOH (Scheme 16). 

E. C. Taylor, A. McKillop, and coworkers. Thallium in organic synthesis 49. Oxidative rearrangement of chalcone dimethylketals to methyl-2,3-diaryl-3-methoxypropanoates with thallium(m) trinitrate in trimethylorthoformate. J. Org. Chem., 1977, 42, 4167 50. A convenient synthesis of thallium(i) cyanide, a useful reagent in organic synthesis (for conversion of aroyl chlorides to aromatic a-ketonitriles). J. Org. Chem., 1978, 43, 2280 51. Oxidation of enolizable ketones to a-nitratoketones by thallium(in) nitrate in acetonitrile. 

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