Gürol Okay

A Novel Synthesis Towards Ellipticine and Its Derivatives. Synthesis of a New Precursor Compound

Abstract The synthesis of a new precursor compound 3, which may be important for the synthesis of ellipticine and its derivatives, was described. Many new intermediates 5–10 have also been synthesized.

Structural investigations of 1,2,3,4-tetrahydrocarbazole derivatives. I. 2,3-Dihydro-9-(phenylsulfonyl)carbazole-4(1H)-one and 1,2,3,4-tetrahydrocarbazole-1-spiro-2'-[1,3]dithiolane

Rings A and B of the title compounds, C 18 H 15 NO 3 S (1) and C 14 H 15 NS 2 (2), are planar while the hydrogenated C rings are not. The rings in the tetrahydrocarbazole skeleton are twisted with respect to each other

Synthesis of Substituted Benzofuran3(2h)one Enamines

Abstract The first examples of substituted 3-(1-pyrrolidinyl)benzofurans and 3-(1-morpholinyl)benzofuran were successfully synthesized from the reactions of secondary heterocyclic amines and substituted benzofuran3(2H)ones.

[2+2] CYCLOADDITIONS OF BENZOFURAN-3(2H)-ONE ENAMINES WITH DIMETHYL ACETYLENEDICARBOXYLATE

(2000). [2+2] CYCLOADDITIONS OF BENZOFURAN-3(2H)-ONE ENAMINES WITH DIMETHYL ACETYLENEDICARBOXYLATE. Organic Preparations and Procedures International: Vol. 32, No. 6, pp. 584-588.

The Stereoselective Synthesis of Disubstituted E, Z-Diene Ester

Abstract The new method for the stereoselective synthesis of disubstituted diene ester was successfully applied to a highly stereoselective synthesis of E, Z-diene ester (1).

Synthesis of Various 2,8-Cyclooctadiene-1,2-dicarboxylates

Reactions of enamines with electrophilic acetylenes such as dimethyl acetylenedicarboxylate (DMAD), diethyl acetylenedicarboxylate (DEAD), methyl propiolate and dicyanoethylene have been extensively studied in the literature.1,2 The two carbon ring expansions which involve [2 + 2] cycloaddition of enamines of cyclic ketones and electron deficient acetylenes followed by thermal rearrangement of the resulting fused cyclobutenes is an established and useful method in organic synthesis. These ring enlargement reactions have been successfully used in the synthesis of medium-sized heterocycles,3–5 azulenes,6 and several natural products including muscone,7 steganone, and velleral.8,9 The mechanism of the reaction of enamine with acetylene derivatives has been thoroughly investigated.1,10–13 It was found that enamine reactions with acetylene derivatives can be affected by many factors. First, a solvent has a remarkable effect on the course of the reactions of acetylene derivatives with enamines. In non-polar solvents, [2 + 2] cycloaddition takes place while in polar solvents pyrrolizines are formed by reaction of the initially formed linear Michael adducts of enamine and acetylene derivatives.13–15 Secondly, the amine moiety on the enamine also affects the rate of reaction and the formation of products as well. The [2 + 2] cycloadducts with the more effective π -electron donating 1-pyrrolidinyl group undergo a thermal rearrangement at room temperature while the analogues with 1-pyrrolidinyl or 4-morpholinyl substituent at the bridgehead sp3-hybridized carbon are thermally stable at room temperature.16 When 2-methylcyclohexanone was subjected to enamine formation reaction with pyrrolidine or morpholine, isomeric mixtures were obtained in each case as reported in the literature.17 6-Methyl-1-(1-pyrrolidinyl)-1-cyclohexene (1) and 2-methyl-1-(1pyrrolidinyl)-1-cyclohexene (3) were obtained in 87% yields in a ratio of 10:90%. Furthermore 6-methyl-1-(4-morpholinyl)-1-cyclohexene (2) and 2-methyl-1-(4-morpholinyl)1-cyclohexene (4) were formed in 79% yield in a 48:52% ratio. We obtained the same results. The [2 + 2] cycloaddition reactions occured with only isomers 1 and 2 which is

4-Methylcarbazole-3-carboxylic acid

The title compound, C(14)H(11)NO(2), consists of a carbazole skeleton with carboxylic acid and methyl groups at positions 3 and 4, respectively. Molecules are linked about inversion centres by O-H.O hydrogen bonds [O.O 2.620 (3) A] to form centrosymmetric dimers.