Chemo- and Diastereoselective Michael–Michael-Acetalization Cascade for the Synthesis of 1,3-Indandione-Fused Spiro[4.5]decan Scaffolds

A novel, organobase-catalyzed and highly chemoselective Michael–Michael-acetalization cascade is presented for the efficient synthesis of spiro-indandione skeletons. Following this very simple protocol, a broad range of products was obtained in good yields with excellent diastereocontrol. The role of steric factors in the acetalization step was evaluated

Chemo- and Diastereoselective Michael–Michael-Acetalization Cascade for the Synthesis of 1,3-Indandione-Fused Spiro[4.5]decan Scaffolds

A novel, organobase-catalyzed and highly chemoselective Michael–Michael-acetalization cascade is presented for the efficient synthesis of spiro-indandione skeletons. Following this very simple protocol, a broad range of products was obtained in good yields with excellent diastereocontrol. The role of steric factors in the acetalization step was evaluated

Diastereoselective Synthesis of Rauhut–Currier-Type Adducts via an Unexpected α‑Addition of α,β-Unsaturated γ‑Butyrolactams to Coumarin Derivatives

A novel, base-catalyzed and highly diastereoselective direct Michael addition-isomerization sequence is presented for the efficient synthesis of Rauhut–Currier-type adducts. An unexpected α-addition of γ-butyrolactam onto the 3-acyl coumarin derivatives was observed rather than the γ-addition, which is more common. The adducts could further undergo hydrolysis/decarboxylation to generate the products which are equivalent to those obtained by α-addition of γ-butyrolactam onto the corresponding chalcones

The clinicopathological characteristics of different gender in 305 OSCC patients.

<p>The clinicopathological characteristics of different gender in 305 OSCC patients.</p

The association between tumor PD-L1 expression and clinical parameters in 305 OSCC patients.

<p>The association between tumor PD-L1 expression and clinical parameters in 305 OSCC patients.</p

Univariate analysis of the influence of various parameters on overall survival in OSCC patients.

<p>Univariate analysis of the influence of various parameters on overall survival in OSCC patients.</p

Multivariate analysis of the influence of various parameters in PD-L1 on overall survival in OSCC patients.

<p>^agender, smoking, stage and grade were adjusted in multivariate analysis.</p><p>Multivariate analysis of the influence of various parameters in PD-L1 on overall survival in OSCC patients.</p