“…The reaction is completed by attack of a second methoxide ion on oxirane 10 to yield product 11 (step e). The procedure worked for a large range of structural types; the following illustrative α-hydroxydimethylacetals ( 12 − 17 ) were obtained from the precursor ketones. − …”
Section: Prefacementioning
confidence: 99%
“…The steps that we considered to occur in this reaction are as follows: step a, dissociation of the polymeric iodosylbenzene or hydrolysis of iodobenzene diacetate The reaction is completed by attack of a second methoxide ion on oxirane 10 to yield product 11 (step e). The procedure worked for a large range of structural types; the following illustrative R-hydroxydimethylacetals (12)(13)(14)(15)(16)(17) were obtained from the precursor ketones. [10][11][12][13] Use of the reaction for the construction of the dihydroxyacetone side chain at the 17β-acetyl position in the pregnane series (Scheme 6) is noteworthy.…”
Section: Prefacementioning
confidence: 99%
“…The procedure worked for a large range of structural types; the following illustrative R-hydroxydimethylacetals (12)(13)(14)(15)(16)(17) were obtained from the precursor ketones. [10][11][12][13] Use of the reaction for the construction of the dihydroxyacetone side chain at the 17β-acetyl position in the pregnane series (Scheme 6) is noteworthy. 14 Other ste- roids containing a keto group at C3 in the A-ring did not give the dimethylacetal product, presumably due to steric constraints in the steroidal ring system, but rather followed a Favorskii type ring contraction.…”
The synthetic utility of organohypervalent iodine reagents will be illustrated by their use in the alpha-hydroxydimethylacetal formation reaction from enolizable ketones, alpha-hydroxylation, alpha-tosyloxylation, alpha-alkoxylation and arylation of ketones, carbon-carbon bond formation, and intramolecular cyclopropanation using iodonium ylides. The uses of these reagents in the Hunsdiecker reaction of carboxylic acids and Hofmann rearrangement of carboxamides is presented. Specific transformation in the cubane series are discussed. The syntheses of a wide range of heterocycle structures are also presented. A unifying pathway for virtually all these diverse reactions is offered; the central features being initial attack at the iodonium center, ligand coupling, with reductive elimination of iodobenzene to yield the product.
“…The reaction is completed by attack of a second methoxide ion on oxirane 10 to yield product 11 (step e). The procedure worked for a large range of structural types; the following illustrative α-hydroxydimethylacetals ( 12 − 17 ) were obtained from the precursor ketones. − …”
Section: Prefacementioning
confidence: 99%
“…The steps that we considered to occur in this reaction are as follows: step a, dissociation of the polymeric iodosylbenzene or hydrolysis of iodobenzene diacetate The reaction is completed by attack of a second methoxide ion on oxirane 10 to yield product 11 (step e). The procedure worked for a large range of structural types; the following illustrative R-hydroxydimethylacetals (12)(13)(14)(15)(16)(17) were obtained from the precursor ketones. [10][11][12][13] Use of the reaction for the construction of the dihydroxyacetone side chain at the 17β-acetyl position in the pregnane series (Scheme 6) is noteworthy.…”
Section: Prefacementioning
confidence: 99%
“…The procedure worked for a large range of structural types; the following illustrative R-hydroxydimethylacetals (12)(13)(14)(15)(16)(17) were obtained from the precursor ketones. [10][11][12][13] Use of the reaction for the construction of the dihydroxyacetone side chain at the 17β-acetyl position in the pregnane series (Scheme 6) is noteworthy. 14 Other ste- roids containing a keto group at C3 in the A-ring did not give the dimethylacetal product, presumably due to steric constraints in the steroidal ring system, but rather followed a Favorskii type ring contraction.…”
The synthetic utility of organohypervalent iodine reagents will be illustrated by their use in the alpha-hydroxydimethylacetal formation reaction from enolizable ketones, alpha-hydroxylation, alpha-tosyloxylation, alpha-alkoxylation and arylation of ketones, carbon-carbon bond formation, and intramolecular cyclopropanation using iodonium ylides. The uses of these reagents in the Hunsdiecker reaction of carboxylic acids and Hofmann rearrangement of carboxamides is presented. Specific transformation in the cubane series are discussed. The syntheses of a wide range of heterocycle structures are also presented. A unifying pathway for virtually all these diverse reactions is offered; the central features being initial attack at the iodonium center, ligand coupling, with reductive elimination of iodobenzene to yield the product.
“…Norbornanone (14a) yielded 2-endo-norbornanol-3one 3-(dimethyl acetal) (15a).18 Likewise 7-oxabicyclo[2.2.1]hept-2-one (14b) yields 7-oxabicyclo[2.2.1]hept-2-one-3-endo-ol dimethyl acetal (15b).19 1-Tetralone (16) and 1-indanone (18) yielded the corresponding -hydroxy dimethyl acetal products, 16 -17 and 18 -»• 19, respectively.20 Next we applied the reaction to molecules which contained other potentially oxidizable function groups such as secondary and tertiary amino, thioether, and olefinic. 21 For example, 3-tropanone (20) was converted to 2a-hydroxy-3-tropanone dimethyl acetal (21)…”
A new series of dopamine D4 receptor agonists, 1-aryl-3-(4-pyridinepiperazin-1-yl)propanone oximes, was designed through the modification of known dopamine D4 receptor agonist PD 168077. Replacement of the amide group with a methylene-oxime moiety produced compounds with improved stability and efficacy. Structure-activity relationsips (SAR) of the aromatic ring linked to the N-4-piperazine ring confirmed the superiority of 2-pyridine as a core for D4 agonist activity. A two-methylene linker between the oxime group and the N-1-piperazine ring displayed the best profile. New dopamine D4 receptor agonists, exemplified by (E)-1-(4-chlorophenyl)-3-(4-pyridin-2-ylpiperazin-1-yl)propan-1-one O-methyloxime (59a) and (E)-1-(3-chloro-4-fluorophenyl)-3-(4-pyridin-2-ylpiperazin-1-yl)propan-1-one O-methyloxime (64a), exhibited favorable pharmacokinetic profiles and showed oral bioavailability in rat and dog. Subsequent evaluation of 59a in the rat penile erection model revealed in vivo activity, comparable in efficacy to apomorphine. Our results suggest that the oximes provide a novel structural linker for 4-arylpiperazine-based D4 agonists, possessing leadlike quality and with potential to develop a new class of potent and selective dopamine D4 receptor agonists.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
