16958-42-2Relevant articles and documents
Total Synthesis of Haliclonin A
Jin, Yuan,Orihara, Kensuke,Kawagishi, Fumiki,Toma, Tatsuya,Fukuyama, Tohru,Yokoshima, Satoshi
, p. 9666 - 9671 (2021)
The total synthesis of haliclonin A was accomplished. Starting from 3,5-dimethoxybenzoic acid, a functionalized cyclohexanone fused to a 17-membered ring was prepared through a Birch reduction/alkylation sequence, ring-closing metathesis, intramolecular cyclopropanation, and stereoselective 1,4-addition of an organocopper reagent to an enone moiety. Reductive C?N bond formation via an N,O-acetal forged the 3-azabicyclo[3.3.1]nonane core. The allyl alcohol moiety was constructed by a sequence involving stereoselective α-selenylation of an aldehyde via an enamine, syn-elimination of a selenoxide, and allylation of the aldehyde with an allylboronate. Formation of the 15-membered ring containing a skipped diene was achieved by ring-closing metathesis, and final transformations led to the synthesis of haliclonin A.
A Metathesis Route to (+)-Orientalol F, a Guaiane Sesquiterpene from Alisma Orientalis
Zahel, Martin,Wang, Yuzhou,J?ger, Anne,Metz, Peter
, p. 5881 - 5886 (2016)
The synthesis of (+)-orientalol F (1) started with aldehyde 6, which is available from (R)-limonene in two steps. Wittig reaction of 6 with unsaturated ylide 7 to give a tetraene, and subsequent ring-closing metathesis yielded hydroazulene 4, selective ep
Evolution of an oxidative dearomatization enabled total synthesis of vinigrol
Yang, Qingliang,Draghici, Cristian,Njardarson, Jon T.,Li, Fang,Smith, Brandon R.,Das, Pradipta
supporting information, p. 330 - 344 (2014/01/06)
The evolution of the synthetic strategy resulting in a total synthesis of vinigrol is presented. Oxidative dearomatization/intramolecular Diels-Alder cycloaddition has served as the successful cornerstone for all of the approaches. Extensive radical cyclization efforts to form the tetracyclic core resulted in interesting and surprising reaction outcomes, none of which could be advanced to vinigrol. These cyclization obstacles were successfully overcome by using Heck instead of radical cyclizations. The total synthesis features a trifluoroethyl ether protecting group being used for the first time in organic synthesis. The logic of its selection and the group's importance beyond protecting the C8a hydroxyl group is presented along with a discussion of strategies for its removal. Because of the compact tetracyclic cage the route is built around many unusual reaction observations and solutions have emerged. For example, a first of its kind Grob fragmentation reaction featuring a trifluoroethyl leaving group has been uncovered, interesting interrupted selenium dioxide allylic oxidations have been observed as well as intriguing catalyst and counterion dependent directed hydrogenations.
