合成路线1

The Eastern fragment (XIV) was derived from 2',4'-dihydroxy-3'-propylacetophenone (VII). This material could be converted into (X) using identical procedures to those developed in house for the synthesis of SC-41930. (X) was resolved into its two homochiral components using enzymatic methods (Amano lipase AK, pH 7.4 buffer followed by selective methylation [CH3l, KHCO3, DMSO] and recrystallization. The overall yield for this process was 33% [based on a resolution yield of 40%]) and afforded the desired (-)-isomer (XII) in > 99% e.e. This material was silylated (TBDMS chloride, DMF, imidazole) and reduced to the primary carbinol with DIBAL-H. Conversion to the Eastern fragment (XIV) was accomplished by an efficient 3-step process involving triflation (Tf2O, CH2Cl2), homologation with lithium tert-butyl acetate and protective group removal/transesterification with ethanolic hydrogen chloride (92% for the three steps). The overall yield of Eastern fragment (> 99% e.e.) was 17% based on 2',4'-dihydroxy-3'-propylacetophenone (VII) as starting material.