Asymmetric synthesis of tert-butyl ((1R,4aR,8R,8aR)-1-hydroxyoctahydro-1H-isochromen-8-yl)carbamate

The asymmetric synthesis of methyl (E)-4-((1R,2S,3R)-3-amino-2-((E)-2-methoxycarbonyl-eten-1-yl)cyclohexyl)but-2-enoate 14 has been achieved from dimethyl (2E,7E)-nona-2,7-dienedioate 2. A key step is the asymmetric synthesis of 1-hydroxyoctahydro-1H-isochromene derivative 5 whose X-ray analysis corroborated the stereochemistry of the new stereocenters. The asymmetric synthesis of the isochromenyl acetate derivative 11 shows the potential of this methodology for fused cyclohexanic system heterocyclic synthesis.     

高效大量合成AF-5的中间体:(4aR,7R)-1-丁基 -4a-甲基-7-(1-甲基-1-羟乙基)-2(1H)-八氢萘酮

化合物(4 aR,7R)-1-丁基-4 a-甲基-7-(1-甲基-1-羟乙基)-2(1H)-八氢萘酮是合成AF-5的重要中间体,传统方法是在强碱叔丁醇钾的作用下对化合物(4 aR,7R)-4 a-甲基-7-(1-甲基-1-羟乙基)-2(1H)-八氢萘酮进行烷基化反应而得到的.为了使操作更方便、安全,适合大量制备,并提高收率,作者探索了多种碱性条件,并选择氢氧化钾的叔丁醇溶液代替叔丁醇钾,最终使该步烷基化反应可以工业化.     

Synthesis of 2S, 3aS, 7aS- and of 2S, 3aR, 7aR-Perhydroindole-2-carboxylic acid derivatives from L-aspartic acid

Using carbon radicals generated by photolysis of N-hydroxy-2-thio-pyridone esters (mixed anhydrides) the chiral centre of L-aspartic acid has been easily incorporated into the perhydroindole structure of the title compounds.     

Synthesis of 3,7—Disubstituted 1,4—Benzodiazepin—2—one

A series of 3-methoxycarbonylpropoxy-7-(imidazol-4-ylpropinamide)-1,3-dihydrogen-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-ones,as farnesyltransferase(Ftase) inhibitors,were synthesized. The preparation of the key intermediate,7-amino-3-methoxycabonylpropoxy-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-one,was improved.     

A convenient synthesis of enantiopure (4aS,7aR)-1,4,4a,7a-tetrahydrocyclopenta[c]pyran-3,7-dione

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Enantiospecific synthesis of (6R,7S,8aR)-dihydroxyindolizidine and (6R,7R,8S,8aR)-trihydroxyindolizidine from D-glucose.

Enantiospecific syntheses of (6R,7S,8aR)-dihydroxyindolizidine (1) and (6R,7R,8S,8aR)-trihydroxyindolizidine (2) from readily available methyl 2-azido-4,6-O-benzylidene-2-deoxy-α-D-altropyranoside (5) are described.