Diastereoselective Total Synthesis of (±)-SchindilactoneA, Part3: The Final Phase and Completion

• Published in: Chemistry, an Asian journal an Asian journal, 2012-10, Vol.7 (10), p.2341
• Main Authors: Ren, Wei-Wu, Chen, Zhi-Xing, Xiao, Qing, Li, Yong, Sun, Tian-Wen, Zhang, Zi-Yang, Ye, Qin-Da, Meng, Fan-Ke, You, Lin, Zhao, Ming-Zhe, Xu, Ling-Min, Tang, Ye-Feng, Chen, Jia-Hua, Yang, Zhen
• Format: Article
• Language: English
• Subjects: Chemistry
• ISSN: 1861-4728; 1861-471X
• DOI: 10.1002/asia.201200365

The final phase for the total synthesis of (±)-schindilactoneA (1) is described herein. Two independent synthetic approaches were developed that featured Pd-thiourea-catalyzed cascade carbonylative annulation reactions to construct intermediate 3 and a RCM reaction to make intermediate 4. Other important steps that enabled the completion of the synthesis included: 1)A Ag-mediated ring-expansion reaction to form vinyl bromide 17 from dibromocyclopropane 30; 2)a Pd-catalyzed coupling reaction of vinyl bromide 17 with a copper enolate to synthesize ketoester 16; 3)a RCM reaction to generate oxabicyclononenol 10 from diene 11; 4)a cyclopentenone fragment in substrate 8 was constructed through a Co-thiourea-catalyzed Pauson-Khand reaction (PKR); 5)a Dieckmann-type condensation to successfully form the Aring of schindilactoneA (1). The chemistry developed for the total synthesis of schindilactoneA (1) will shed light on the synthesis of other family members of schindilactoneA [PUBLICATION ABSTRACT].