79950-42-8Relevant articles and documents
TBuO 2H/Cu(acac) 2-Mediated Intramolecular Oxidative Lactonization of o -Allyl Arylaldehydes: Synthesis of 1-Oxoisochromans
Chang, Meng-Yang,Lai, Kai-Xiang,Chen, Kuan-Ting
, p. 527 - 537 (2020/10/19)
A concise route for the tBuO 2H/Cu(acac) 2-mediated synthesis of 1-oxoisochromans is described. This includes: (i) oxidation of oxygenated o -allyl arylaldehydes and (ii) sequential intramolecular lactonization of the resulting olefin-containing benzoic acids. A plausible mechanism is proposed and discussed.
Synthesis of treprostinil: Key claisen rearrangement and catalytic pauson-khand reactions in continuous flow
García-Lacuna, Jorge,Domínguez, Gema,Blanco-Urgoiti, Jaime,Pérez-Castells, Javier
, p. 9489 - 9501 (2019/11/14)
A new synthesis of treprostinil is described using a plug flow reactor in two of the key steps. First, a Claisen rearrangement reaction is described in scaled flow at multigram amounts. Yields and selectivity of this step are sharply improved compared to those from previous syntheses. Second, the key Pauson-Khand reaction in flow is described under catalytic conditions with 5 mol% of cobalt carbonyl and only 3 equiv. of CO. Scaling up of this reaction safely ensures a good yield of an advanced intermediate which is transformed into treprostinil in three steps. Other improvements are the introduction of the carboxymethyl chain into the phenol from the beginning to reduce the protection-deprotection steps. The synthesis is completed in 14% global yield after 12 linear steps from (S)-epichlorhydrin.
Synthesis of 3-Azidopiperidine Skeleton Employing Ceric Ammonium Nitrate (CAN)-Mediated Regioselective Azidoalkoxylation of Enol Ether: Total Synthesis of D2 Receptor Agonist (±)-Quinagolide
Chavan, Subhash P.,Kadam, Appasaheb L.,Lasonkar, Pradeep B.,Gonnade, Rajesh G.
supporting information, p. 7011 - 7014 (2018/11/23)
The total synthesis of (±)-quinagolide, which is a D2 receptor agonist, was accomplished via a ceric ammonium nitrate (CAN)-mediated regioselective azidoalkoxylation of enol ether route. Key features of the synthesis include Claisen rearrangement, PPTS (pyridinium p-toluenesulfonate)-catalyzed one-pot acetal deprotection, followed by a diastereoselective Henry reaction, which enables construction of the required trans ring junction and CAN-mediated regioselective azidoalkoxylation of enol ether. The PPTS-catalyzed intramolecular diastereoselective Henry reaction to fix three contiguous stereocenters on tetrahydronaphthalene and the first-of-its-kind synthesis of the 3-azidopiperidine skeleton, using a CAN-mediated regioselective azidoalkoxylation of enol ether, are important findings of the present work.
