中文名称 | 英文名称 | CAS号 | 化学式 | 分子量 |
---|---|---|---|---|
—— | methyl 5,5-dichloro-4-oxo-2-n-propyl-1-trimethylsilyloxy-2-cyclopentene carboxylate | 852991-64-1 | C13H20Cl2O4Si | 339.291 |
—— | 2-t-butyldimethylsilyloxy-2,2-dichloro-3-oxo-4-propylcyclobutanecarboxylic acid (S)-(2,2-diphenyl)cyclopentyl ester | 852991-60-7 | C31H40Cl2O4Si | 575.648 |
—— | 2-t-butyldimethylsilyloxy-2,2-dichloro-3-oxo-5-propylcyclopentanecarboxylic acid (S)-(2,2-diphenyl)cyclopentyl ester | 852991-61-8 | C32H42Cl2O4Si | 589.675 |
An asymmetric formal synthesis of the fungal metabolites ()-cryptosporiopsin and ()-3-deschloro crypto sporiopsin has been accomplished. The asymmetry was introduced via a diastereoselective [2+2]-cycloaddition between an enoxy-ester, bearing a bulky chiral auxiliary, and dichloroketene. Diastereomeric ratios of 10:1 were obtained from the reaction mixture, but this could be increased by simple crystallization. Completion of the synthesis was only accomplished after the serendipitous discovery of a base-catalyzed rearrangement to furnish the requisite 3-chloroenone moiety.Key words: diastereoselective [2+2]-cycloaddition, rearrangement, chiral auxiliary.