147963-63-1Relevant articles and documents
Enantioselective total synthesis of the (-)-(6R,11R,14S)-isomer of colletallol
Amigoni, Sonia J.,Toupet, Loic J.,Le Floc'h, Yves J.
, p. 6374 - 6378 (1997)
The total synthesis of the (-)-(6R,11R,14S)-isomer of colletallol was achieved in 15 steps. The key steps of the sequence were the building of the macrocycle via two consecutive Wittig reactions, the first intermolecular and the second intramolecular, instead of the classical macrolactonization methods.
The total synthesis of D-chalcose and its C-3 epimer
Sun, Jun,Fan, Song,Wang, Zhan,Zhang, Guoning,Bao, Kai,Zhang, Weige
supporting information, p. 2620 - 2624 (2014/01/06)
We completed a new and efficient synthesis of D-chalcose (I) and the first synthesis of its C-3 epimer (I') in nine steps with overall yields of 23% and 24%, respectively. The key steps in the sequence were the formation of the stereocenter on C3 via Grignard reaction, the introduction of the stereogenic center on C2 by Sharpless asymmetric dihydroxylation, the protection of the C1 and C2 hydroxy groups with tert-butyldimethylsilyl trifluoromethanesulfonate (TBSOTf), and the selective cleavage of the primary OTBS ether using catalytic DL-10-camphorsulfonic acid (CSA) in MeOH.
Biomimetic synthesis of the pentacyclic nucleus of ptilomycin A
Snider,Shi
, p. 549 - 557 (2007/10/02)
The methyl ester of the pentacyclic nucleus of ptilomycalin A (9) has been prepared by an efficient, convergent, biogenetic, 14-step route. The key steps involve the conversion of acyclic bis enone 39 to 9 in four steps. Michael addition of O-methylisourea to 39 afforded 52% of a mixture of isoureas 40 and 41, which were both converted to 72% of tricyclic aminals 42 and 43 by ammonolysis. Deprotection of the silyl ethers with HF and cyclization with Et3N in MeOH afforded 9 (~34% from 42) and the diastereomer 45 with an equatorial methyl ester group (~26% from 42).
