Kozo Shishido

Stereoselective Construction of Substituted Chromans by Palladium-Catalyzed Cyclization of Propargylic Carbonates with 2-(2-Hydroxyphenyl)acetates

Highly substituted chromans have been constructed in a highly stereoselective manner by a palladium-catalyzed reaction of propargylic carbonates with 2-(2-hydroxyphenyl)acetates. Enantioselective reactions also successfully proceeded to give the optically active chromans with high enantioselectivity.

Enantiocontrolled Total Syntheses of Breviones A, B, and C

Enantiocontrolled total syntheses of the breviones A, B, and C have been accomplished using a highly diastereoselective oxidative coupling of an α-pyrone with a tricyclic diene prepared from an optically pure Wieland-Miescher ketone derivative through the 7-endo-trig mode of acyl radical cyclization.

Total Syntheses of Enokipodins A and B Utilizing Palladium-Catalyzed Addition of An Arylboronic Acid to An Allene

The enantioselective total syntheses of enokipodins A and B, alpha-cuparenone-type sesquiterpenoids with antimicrobial activity, have been achieved. The key step is the enantiospecific construction of the quaternary carbon center using a palladium-catalyzed addition of an arylboronic acid to an allene followed by an Eschenmoser-Claisen rearrangement.

Tripterygium wilfordii var. regelii which are interleukin-1 inhibitors

Abstract Seven new quinoide-type diterpenes were isolated from the stems of Tripterygium wilfordii var. regelii and their structures were established on the basis of spectroscopic and chemical evidence. The isolated compounds showed extremely potent inhibitory activities against interleukin-lα and β releases for human peripheral mononticlear cells.

Cycloaromatization of a 10-membered enediyne derivative via an allenic sulfone intermediate and its DNA cleaving activity

Abstract Synthesis of the sulfone containing 10-membered enediyne derivative 3 and its cycloaromatization in basic conditions via an allenic sulfone intermediate as well as its DNA cleaving activities are described.

Triptoquinone A and B novel interleukin-1 inhibitors from Tripterygium wilfordii var Regeli

Abstract Novel interleukin-1 inhibitors, triptoquinone A (1) and B(2), have been isolated from Tripterygium wilfordii v a r regelli, and their structures were elucidated mainly by spectroscopic methods including X-ray.

Enantioselective total synthesis of (−)-equisetin using a Me3Al-mediated intramolecular Diels–Alder reaction☆

Abstract An efficient and enantioselective total synthesis of (−)-equisetin 1 has been accomplished using a diastereoselective Me 3 Al-mediated intramolecular Diels–Alder (IMDA) reaction as a key reaction step.

Diastereoselective Intramolecular Carbamoylketene/Alkene [2 + 2] Cycloaddition: Enantioselective Access to Pyrrolidinoindoline Alkaloids

A novel and highly diastereoselective intramolecular carbamoylketene/alkene [2 + 2] cycloaddition has been developed, and the methodology was successfully applied to the enantioselective syntheses of (-)-esermethole and Takayamas intermediate for (+)-psychotrimine.

Synthesis of a sulfulr-containing 10-membered enediyne model compound related to the esperamicin/calicheamicin/dynemicin agylcones

Abstract Synthesis of the 10-membered heterocyclic enediyne 4 and its conversion to the benzenoid adduct 10 via the Bergman reaction are described.

Total Synthesis of Penostatin B

The first total synthesis of penostatin B has been accomplished by using a highly diastereoselective Pauson-Khand reaction and an efficient relay ring-closing metathesis for the construction of the basic carbon skeleton of the natural product as the key steps.