Morphine has been a target for synthetic chemists since Robinson proposed its correct structure in 1925, resulting in a large number of total syntheses of morphine alkaloids. Here we report a total synthesis of (±)-morphine that employs two key strategic cyclizations: 1) a diastereoselective light-mediated cyclization of an O-arylated butyrolactone to form a tricyclic cis-fused benzofuran and 2...

Althought there are several reported synthetic routes to strychnine, one of the most widely recognized alkaloids, we report an unexplored route with an oxidative dearomatizing process mediated by hypervalent iodine as the key step. The new syntheses of isostrychnine and strychnine have been achieved from an readily available phenol in nine and ten steps. In addition to the key step, these synth...

SmI(2)/H(2)O reduces cyclic 1,3-diesters to 3-hydroxyacids with no over reduction. Furthermore, the reagent system is selective for cyclic 1,3-diesters over acyclic 1,3-diesters, and esters. Radicals formed by one-electron reduction of the ester carbonyl group have been exploited in intramolecular additions to alkenes. The ketal unit and the reaction temperature have a marked impact on the dias...

Intramolecular photoinduced cyclizations are investigated in photoprecursors assembled in a modular fashion via a Diels-Alder reaction of acetylenic dienophiles with subsequent Michael additions of aromatic ketones to install a chromophore capable of initiating Paternò-Büchi cycloadditions or radical cyclization cascades. The protolytic oxametathesis in these systems allows for rapid access to ...

A polyanionic supramolecular assembly (1) is shown to catalytically cyclize the monoterpene citronellal and two homologues. In contrast to cyclization in acidic aqueous solution, the hydrophobic interior of 1 prevents the capture of reactive intermediates by water. This effect was also observed in the gold-catalyzed cycloisomerization of an enyne. Due to the steric confinement of the catalyst's...

The 1,6-conjugate addition of nucleophiles to dienyl diketones produces either cyclopentenone or 2H-pyran products with high selectivity through either Nazarov (4π) or 6π electrocyclization, respectively. The outcome of the reaction is dependent upon the nature of the nucleophile used. Nucleophiles that are anionic or easily deprotonated exclusively produce cyclopentenones via Nazarov cyclizati...

In the communication by Peng Wu, Jas S. Ward, Kari Rissanen, and Carsten Bolm, in Issue 4, 2023, pp 522–526 (DOI: 10.1002/adsc.202201408), authors became aware of recently published work which cyclizations to form fluorinated versions a benzo[d][1,3,2]dithiazole 1-oxide 1-imino-benzo[d][1,3,2]-dithiazole 1,3-dioxide were reported: T. Duhail, M. Zhu, C. Rombault, G. Dagousset, Messaoudi, E. Magn...