The claisen rearrangement in synthesis: acceleration of the johnson orthoester protocol en route to bicyclic lactones
作者:Graham B. Jones、Robert S. Huber、Sotheary Chau
DOI:10.1016/s0040-4020(01)80306-9
日期:1993.1
Catalysis of the Claisenorthoesterrearrangement of triethyl orthoacetate and a number of 2-cycloalken-1-ols has been achieved using acidic catalysis and brief microwavethermolysis in DMF. Unlike conventional methods of thermolysis, very high yields of rearranged products are typically obtained in less than ten minutes, and the Claisen products themselves require no further purification. The synthetic
The 5-exo-dig radical cyclisation reaction of the bromoacetals 9, obtained from the enol ethers 8, and treatment of the resulting hemiacetal 10 with JonesⲠreagent transforms the cyclic ketones 7 and 12 into α-spiro-β-methylene-γ-butyrolactones 11 and norbakkenolide-A 2.
Synthetic studies towards daphniyunnine B: Construction of AC bicyclic skeleton with two vicinal all carbon quaternary stereocenters
作者:Haiyu Sun、Guangmiao Wu、Xingang Xie
DOI:10.1016/j.cclet.2019.06.049
日期:2019.8
Abstract The AC bicyclic skeleton of daphniyunnine B with the required 3 stereocenters (C4, C5 and C8) was accomplished in a concise route which featured two Claisen-type rearrangement reactions to construct the required vicinal all carbon quaternary stereocenters (C5 and C8) and an intramolecular iodo-cyclization reaction to assemble the cis-confused bicyclic lactam.