Reaction of (2,4,5-trimethoxyphenyl)(2-hydroxyphenyl)methanone with ceric ammonium nitrate furnished the xanthone, 2,3-dimethoxy-9H-xanthen-9-one. Under the same conditions the related (1,4-dimethoxynaphthalen-2-yl)(2-hydroxyphenyl)methanone resulted in the formation of 12a-methoxy-5H-benzo[c]xanthenes 5,7(12aH)-dione. Other examples of this novel transformation are also outlined.

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The Suzuki–Miyaura coupling reaction between (1,4,5‐trimethoxynaphthalen‐2‐yl)boronic acid and 2‐iodo‐3‐methoxy‐5‐methylbenzaldehyde gave the intermediate 3‐methoxy‐5‐methyl‐2‐(1,4,5‐trimethoxynaphthalen‐2‐yl)benzaldehyde. Conversion of this benzaldehyde into the alkyne 2‐(2‐ethynyl‐6‐methoxy‐4‐methylphenyl)‐1,4,5‐trimethoxynaphthalene was accomplished through a Corey–Fuchs reaction. Exposure of the derived acetylene to a catalytic platinum(II)‐mediated ring closure gave the required tetracyclic aromatic product, 1,7,8,12‐tetramethoxy‐3‐methyltetraphene, which was then converted into tetrangulol. Exposure of the related 3‐methoxy‐5‐methyl‐2‐(1,4,5‐trimethoxynaphthalen‐2‐yl)benzaldehyde O‐phenyloxime to microwave irradiation in an ionic liquid yielded 1,10,12‐trimethoxy‐8‐methylbenzo[c]phenanthridine, instead of the desired natural product phenanthroviridone.

A study of the hydroformylation of 4-methylpent-l-ene has shown that olefin isomerisation involves stepwise migration of the double-bond along the carbon chain. Under typical ' I 0 x 0 " reaction conditions, the rate of isomerisation is very high, increasing with temperature and catalyst concentration. The aldehydes formed in the hydroformylation of 4-methylpent-l-ene have been identified and quantitatively determined a t intermediate levels of conversion. There appears to be no rearrangement of any complex involved in the reactions. It is proposed that the isomerisation involves a x-bonded complex which does not take part in hydroformylation.THOUGH it is known that the double bond of an olefin may migrate during the " 0x0 " synthesis, very little quantitative work on this aspect has been published. Pino, Pucci, and Piacenti found very little such migration in the hydroformylation of (+)-(S)-3methylpent-l-ene under conventional " 0x0 " conditions. In a study of the isomerisation catalysed by iron pentacarbonyl, Manuel concluded that rearrangement occurs within the complex species involved without the formation of intermediate olefins. To provide quantitative data on the fate of an olefin during the " 0 x 0 " reaction, the composition of the reaction mixture as a function of time has been studied during the cobalt-catalysed hydroformylation of 4-methylpent-l-ene.