Diazomethane syntheses

Scope. Epoxides have been prepared from a wide variety ot carbonyl compounds by diazomethane synthesis, in yields ranging freon a few percent to nearly quantitative. No attempt will be made here to present a complete catalogue of reactions, inasmuch as this has been done elsewhere.4 6-463 A few additional examples have appeared since then, which are included in the present text. Reference... 

In the case of D-psicose14 and D-sorbose80 the fceto-pentaacetates, as well as some of their derivatives, have been prepared by the diazomethane synthesis. The only crystalline product which was isolated from the low temperature acetylation of D-psicose137 was the fceto-pentaacetate. /ceabsorption spectrum indicated the presence of the ketonic group and its structure was further verified by catalytic hydrogenation,102 followed by acetylation, in which case both L-iditol and... 

Key a, enzymic synthesis b, diazomethane synthesis c, bacterial oxidation d, pyridine rearrangement. 

Syntheses with diazomethane Synthesis with addition of 1 C-atom Diazomethyl ketones from carboxylic acid chlorides... 

By three reaction types (5), 4 and (5) in Thble 2-1 of Sect. 2.2, ketones or aldehydes are used as starting materials. Therefore, it is reasonable to treat them together in this section. At the end (Subsection 2.5.4) a related diazomethane synthesis (depicted many decades ago by Staudinger) will be added, although it is not strictly related to this section. From the synthetic point of view, it is not particularly interesting, but mechanistically it is worthy of discussion because nitrilimine, an isomer of diazomethane, is probably formed as a steady-state intermediate in this reaction. 

Creary, X. Tosylhydrazone salt pyrolyses Phenyldiazomethanes. Diazomethane synthesis. Org. Syn. 1986, 64, 207-216. 

The 1-deoxyketoses are prepared from the aldehydo-sugar acetates via the diazomethane synthesis (p. 113) 156c). 

A versatile oxirane synthesis via (64) is the sulfur ylide approach (B-75MI50504, cf. 76TL457), which in effect inserts a CR2 group into a carbonyl group (Scheme 71). Older, less generally useful versions of this insertion utilize diazomethane or dibromomethane-butyllithium. 

It is interesting to note that the existence of an isomer of diazomethane with a diazirine structure was never discussed, so the report on its synthesis 61TL612) simultaneously started and ended the discussion on its existence. 

Thnrane dioxide eplsulfone synthesis by reaction of diazomethane with sulfenes or SOg ... 

The constitution of laudanidine was determined by Spath and Bernhauer, who showed that with diazomethane it yields Maudanosine, m.p. 87-8°, and, the reversal of this process, viz, partial demethylation of synthetic Maudanosine by Spath and Burger provided a complete synthesis of Maudanine, which is laudanidine. 

Reactions offluorinated dipoles. In recent years, much effort has been devoted to the preparation of tnfluoromethyl-substituted 1,3-dipoles with the goal of using them to introduce trifluoromethyl groups into five-membered nng heterocycles Fluorinated diazoalkanes were the first such 1,3-dipoles to be prepared and used in synthesis A number of reports of cycloadditions of mono- and bis(tnfluo-romethyl)diazomethane appeared prior to 1972 [9] Other types of fluonne-substi-tuted 1,3-dipoles were virtually unknown until only recently However, largely because of the efforts of Tanaka s group, a broad knowledge of the chemistry of tnfluoromethyl-substituted nitrile oxides, nitnle imines, nitnle ylides, and nitrones has been accumulated recently... 

Synthesis of pyrazolines in reactions of a,(3-enones with diazomethane and hydrazines 97KGS747. 

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