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Diazo Compounds in the Synthesis of O- and S-Containing Macroheterocycles

“…[32] Moreover, it is noted that only 1,3-dioxacycloalkanes containing phenyl substituent in the position 2 of the heterocycle enter into reaction (Scheme 13). This fact is in a good agreement with the mechanism of 1,2-anionic rearrangement.…”

“…It should be noted that the insertion products of the carbenoid particle with C(2)-O(3)-bond of 1,3-doxacyclines and C-H bond of the solvent were not found in the reaction mass. [35] In contrast to the reaction of diazo esters with cyclic acetals containing a phenyl fragment in the 2-position of the heterocycle, which facilitates the reaction [32] on the interaction of α-diazo-β-ketoester with 1,3-dioxacycloalkanes, the activating effect is produced by the substituents in the position 4 of the 1,3-dioxolane and in position 4(5) of 1,3-dioxanes, and corresponding macrocycles are formed with 45-97 % yields.…”

Cyclopropanation of 5-(allyloxymethyl)- and 5-(methallyloxymethyl)-5-ethyl-1,3-dioxanes with methyl diazoacetate

“…In the reaction of N 2 CHCO 2 Me with 1,3-dioxanes in the presence of Rh 2 (OAc) 4 1,4-dioxepane derivatives were synthesized in up to 46% yields. The reaction of methoxycarbonylcarbene at the C-O bond occurs only with 1,3-dioxanes containing a phenyl substituent in the position 2 of the heterocycle [3]. At the same time the reaction of the linear allylacetals with diazocarbonyl compounds in the presence of Cu-or Rh-containing catalysts occurs nonselectively and leads to the formation both of the products of the alkoxycarbonylcarbene insertion into the C-O bond and of the corresponding cyclopropanation products of the double C=C bond [4,5].…”

Reactions of diazoalkanes with unsaturated compounds 15. Catalytic reactions of unsaturated carbonyl compounds and their derivatives with diazomethane

“…It should be noted that the reactions of methyl diazoacetate with cyclic acetals, viz., 2 substituted 1,3 dioxanes, in the presence of copper or rhodium compounds are ac companied by the introduction of methoxycarbonyl carbene at the C-O bond of dioxolane to form esters of 3 substituted 1,4 dioxepane 2 carboxylic acids. 11 In the present study, we examined the influence of the nature of the acetal group and the catalyst on catalytic cyclopropanation of a series of unsaturated compounds, such as trans crotonaldehyde (1a), trans cinnamaldehyde (2a), hex 5 en 2 one (3a), and their acyclic (1b-3b) and cyclic (1c,d-3c,d) derivatives, with diazomethane.…”