32780-08-8Relevant articles and documents
First total synthesis of Debilisone C
Saikia, Bishwajit,Joymati Devi, Thongam,Barua, Nabin C.
, p. 905 - 913 (2013/03/14)
Total synthesis of Debilisone C, a lactone containing conjugated endiyne has been achieved. The adopted strategy involves the stereoselective construction of the five membered lactone ring and the C20 endiyne chain followed by regioselective coupling of both the parts. The lactone was obtained from the oxidative cleavage of the hydroxy olefin which was derived from the benzyl protected S-epichlorohydrine by regioselective epoxide opening with allyl trimethyl silane in presence of a Lewis acid at -78 °C. Takai olefination, Pd0/Ag1 catalyzed cross-coupling reaction and selective substitution of trimethylsilyl groups were successfully utilized to establish the C20 polyyne chain. The final coupling of both the parts have been carried out by alkyl coupling using LDA in THF-DMPU (1 : 1).
Practical synthesis of C1-8 fragment of autolytimycin via a chelation-controlled diastereoselective addition of diisopropenylzinc to α-methoxy aldehyde
Yang, Fan,Feng, Liang,Wang, Nengzhong,Liu, Xuge,Li, Jun,Shen, Yuehai
, p. 9463 - 9468 (2013/10/08)
The C1-8 fragment of autolytimycin was synthesized via a reliable 10-step route capable of delivering 41% overall yield at multi-gram scale. As a key step, a chelation-controlled isopropenylation of α-oxygenated aldehydes was established with a reagent combination of diisopropenylzinc, magnesium halide, and a dichloromethane/toluene mixed solvent. Cram-chelate isopropenylation products dominated for aldehydes with a small α-substituents, such as -OMe and -OBn groups, while the Felkin product could be obtained with a bulky -OTBS group.
Cyclopropenium-activated cyclodehydration of diols
Kelly, Brendan D.,Lambert, Tristan H.
supporting information; experimental part, p. 740 - 743 (2011/05/04)
The dehydrative cyclization of diols to cyclic ethers via cyclopropenium activation is described. Using 2,3-diphenylcyclopropene and methanesulfonic anhydride, a series of 1,4-and 1,5-diols are rapidly cyclized to furnish tetrahydrofurans and tetrahydropyrans in high yield. Eleven total substrates are shown, including a gram scale cyclization of a diterpene derivative.
