Stereocontrolled Synthesis of the Portimine Skeleton via Organocatalyst-Mediated Asymmetric Stannylation and Stereoretentive C()-C() Stille Coupling.

Our efforts toward the synthesis of the marine natural product portimine are described. The key to the synthesis of the skeleton is a stereoretentive copper-catalyzed C()-C() Stille-type cross-coupling that enables the convergent assembly of functionalized fragments. The core skeleton of portimine was constructed via ring-closing metathesis and transannular acetal formation.

Convergent and Scalable Second-Generation Synthesis of the Fully Functionalized HIJKLMN-Ring Segment of Caribbean Ciguatoxin C-CTX-1.

A highly convergent and scalable second-generation synthesis of the fully functionalized HIJKLMN-ring segment of Caribbean ciguatoxin C-CTX-1, the primary toxin responsible for ciguatera fish poisoning in the Caribbean Sea and the Northeast Atlantic regions, has been accomplished. Key aspects of the synthetic approach include the efficient syntheses of the HI- and KLM-ring fragments on gram scales, a convergent fragment coupling toward the HIJKLM-ring skeleton based on the Suzuki-Miyaura coupling strategy, and optimized iron hydride-catalyzed hydrogen atom transfer-mediated olefin coupling conditions for constructing the N-ring.

Total Synthesis of (-)-Zearalenone and (-)-Zearalanone: A Macrocyclization Strategy by Ni/Zr/Cr-Mediated Reductive Ketone Coupling.

The total synthesis of the resorcylic acid lactones (-)-zearalenone and (-)-zearalanone is described. Our synthetic strategy relies on Ni-, Zr-, and Cr-mediated intramolecular reductive ketone coupling to create 14-membered macrolactones. Notably, the use of CrCl in addition to Ni/Zr-mediated reductive ketone coupling conditions was key for the success of the macrocyclization.

Implementation of multifaceted diagnostic stewardship for infection during the COVID-19 pandemic at a small Japanese hospital.

Objective: infection (CDI) is a common, healthcare-associated infection. However, in Japan, testing for CDI is infrequent, suggesting that its incidence may be underestimated. This study aimed to examine the implementation of a multifaceted, diagnostic stewardship (DS) for CDI in a small Japanese hospital during the coronavirus 2019 pandemic.

Total Synthesis of (-)-Irijimaside A Enabled by Ni/Zr-Mediated Reductive Ketone Coupling.

The total synthesis of marine macrolide glycoside (-)-irijimaside A is described. Key to the synthesis is the convergent fragment assembly enabled by nickel/zirconocene-mediated one-pot reductive ketone coupling. At the last stage of the synthesis, Stille coupling and glycosylation led to the first total synthesis of (-)-irijimaside A.