Total synthesis of (±)-sacidumlignans D and A through Ueno-Stork radical cyclization reaction
Jian-Jian Zhang1, Chang-Song Yan, Yu Peng
1State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, People's Republic of China.
Abstract:
Efficient synthesis of (±)-sacidumlignan D (4) has been successfully achieved employing Ueno-Stork radical cyclization of α-bromo acetal 21 as a key step. Two synthetic approaches for the symmetrical diaryl ketone 19 have been discussed in detail. Notably, sacidumlignan A (1) can be also efficiently synthesized in only 7 steps with 25% overall yield, where acid triggered tandem reaction starting from analogous Ueno-Stork cyclization product 27 played an important role. Moreover, potentially biomimetic conversion from (±)-sacidumlignan D (4) to sacidumlignan A (1) could be realized.
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