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A study of the production of citrinin by Aspergillus niceus and Penicillium citrinum Thom is described. Plots of citrinin production cs. time show that the A. niceus strain investigated produces a higher yield of the antibiotic than does the Penicillium sp. A stepwise chemical degradation of citrinin which is readily adaptable to radioactive tracer techniques is reported. The process involves the degradation of this substance to the known 3-(2-methyl-3,5-dimethoxyphenyl)-2-butanone which is then degraded further by two pathways. One method leads through the ozonizáis X X.ecent years have seen the widespread acceptance of the polyacetate hypothesis (Birch, 1957;

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described above to give 0.08 g (20%) of cts-diol 1 and 0.10 g (24%) of frons-diol 4.Preparation of Benzyl Ether 19.-A dispersion of 53% sodium hydride in mineral oil (3.24 g of sodium hydride, 0.135 mol) was washed with three 50-ml portions of dry pentane under nitrogen.After the final wash the residual pentane was evaporated in vacuo and 60 ml of dimethyl sulfoxide was added dropwise under nitrogen. The resulting solution was stirred at room temperature for 0.5 hr. To this solution was added dropwise over a period of 5 min a solution of 13.70 g (0.090 mol) of 1632 j [a]26d -26.26°( c 2, CHCls)! in 40 ml of dimethyl sulfoxide, and the mixture was stirred at room temperature for 10 hr. To this mixture was added 17.0 g (0.135 mol) of benzyl chloride with stirring over a period of 0.5 hr. The reaction mixture was stirred for 1.0 hr, diluted with 350 ml of ice water, and extracted with pentane. The combined extracts were washed with brine, dried, and concentrated to give 26.87 g of a pale yellow oil from which crystallized 0.46 g of transstilbene. The remaining material was distilled to give 14.55 g (67%) of 19: bp 115-116°( 0.25 mm); [ ]%> -21.79°(c 3.5, CHCla); ir (CC14) 3090 (C=CH), 3050 (aromatic CH), 1640 (C=C), 1380 and 1360 (yem-dimethyl), 1055 (CO), 897 (C=

It is shown that the Smiles rearrangement of 3-amino-2,2'-dipyridyl sulfides and their N-acetyl derivatives can be acid, base, or heat catalyzed. In some cases solvent effects were observed, and examples are cited where the compounds underwent rearrangement in the solid state.The Smiles rearrangement2 is generally considered to be an intramolecular nucleophilic aromatic substitution reaction resulting in the migration of an aromatic ring from one hetero atom to another. The change which occurs can be generally represented by the scheme as shown in Fig. 1, where -YH may be -OH, -SH, -NHR, -CONHR, or -S02NHR, while Z may be O, S, SO, or S02.3 The rearrangement has normally been considered to be base catalyzed and, because a rather intriguing interplay of electronic effects arises from ring substituents, some kinetic data also have been reported.4We became interested in this rearrangement in connection with studies on the transmission of substituent effects across the pyridine ring system. The 3-amino-2,2'-dipyridyl sulfides (1) appeared well suited for our purposes, especially since the Smiles rearrangement of this type of compounds has been reported.6 However, our work clearly required a more concise definition of the conditions necessary for rearrangement and this communication describes some results observed in basic, acidic, and neutral media.

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