Asymmetric oxidation of 3-alkyl-1,2-cyclopentanediones. Part 2: Oxidative ring cleavage of 3-alkyl-1,2-cyclopentanediones: synthesis of 2-alkyl-γ-lactone acids
Ti(OiPr)4/diethyl tartrate/tBuOOH system oxidizes 3-alkyl-1,2-cyclopentanediones resulting in hydroxylated ringcleavage products 2-alkyl-γ-lactone acids, in high enantioselectivity (∼95% ee) and satisfactory isolated yields (up to 55%).
Ti(O i Pr)4 /酒石酸二乙酯/ t BuOOH体系氧化3-烷基-1,2-环戊二酮,生成羟化的环裂解产物2-烷基-γ-内酯酸,对映体选择性高(〜95%ee),令人满意单产(最高55%)。
Synthesis of Novel Acyclic Nucleoside Analogues with Anti-Retroviral Activity
A series of novelacyclic thymine nucleoside analogues were prepared by the Mitsunobu reaction from appropriately protected chiral triols. The enantiomeric triols were obtained from substituted γ-lactone acids, prepared by asymmetric oxidation of 3-substituted-1,2-cyclopentanediones. The cytotoxic activity of new analogues was evaluated on MCF-7 human breast cancer and HeLa cells, and antiviral activities
(R)-(+)-Frontalin (1) and its antipode (1′) were synthesized from (R)-(+)-2-hydroxy-2-methylpentane-1,5-dioic acid 5→2 lactone (2) and its antipode (2′), respectively. This established the absolute configurations of both enantiomers of frontalin and afforded key materials to study the relationship between pheromone activity and chirality.