Yoshiyasu Kitahara

SYNTHESIS OF MERIDINE, CYSTODAMINE, AND RELATED COMPOUNDS INCLUDING IMINOQUINOLINEQUINONE STRUCTURE

Abstract Two aromatic alkaloids, meridine ( 1 ) and cystodamine ( 3 ), and related compounds ( 2, 4, 5 ) were synthesized by hetero Diels-Alder reaction between 4-methoxy- (or 4-chloro-)5,8-quinolinedione and 2-nitrocinnamaldehyde dimethylhydrazone.

Synthetic studies on pentacyclic aromatic alkaloids, kuanoniamine A, 11-hydroxyascididemin, and neocalliactine acetate

Abstract A pentacyclic aromatic alkaloid, kuanoniamine A (6) was synthesized in three steps from 6-methoxybenzothiazole-4,7-dione (8) and 2-aminoacetophenone (9). 11-Hydroxyascididemin (4) was prepared from 5,8-quinolinedione (13, 14) or 1,4-acridinedione (20). The structure of neocalliactine acetate, a derivative of calliactine, was determined to be 5 by total synthesis from 6-methoxy-5,8-quinolinedione (28) and 2-amino-5-methoxyacetophenone (29).

Total synthesis of kuanoniamine A, 11-hydroxy-ascididemin, and neocalliactine acetate

A pentacyclic aromatic alkaloid, kuanoniamine A (5) was synthesized from 6-methoxybenzothiazole-4,7-dione (7) and 2-aminoacetophenone (8). Similarly, 11-hydroxyascididemin (4) was prepared from 6-bromo-4-chloro-5,8-dimethoxyquinoline (12). The structure of neocalliactine acetate, a derivative of calliactine, was determined as 19 by total synthesis from 6-methoxy-5,8-quinolinedione (23) and 2-amino-5-methoxyacetophenone (24)

Total Synthesis of Eupomatidines-1,2, and 3

Three aromatic alkaloids, eupomatidines- 1 (1a), 2 (1b) and 3 (1c), were synthesized from the corresponding 1,4-naphthoquinones (2a, b) by hetero Diels-Alder reaction with 2-butenal dimethylhydrazones (3a, b), followed by one pot annelation of ring A

Synthesis of cystodamine, a pentacyclic aza-aromatic alkaloid

A pentacyclic aza-aromatic alkaloid, cystodamine (6), and its isomer (11) were synthesized from 7-(or 6-)bromo-4-chloro-5,8-quinolinedione (1, 8) and o-nitrocinnam-aldehyde dimethylhydrazone (2) using hetero Diels-Alder reaction.

Synthesis of 2(1H)-quinolinonequinones and 2-alkoxy-quinolinequinones using oxidative demethylation with cerium (IV) ammonium nitrate

2,5,8(1H)-Quinolinetriones (12), 2,5,6(1H)-quinolinetriones (13), 2-alkoxy-5,8-quinolinediones (14), 2,8-dimethoxy-5,6-quinolinedione (15), and 2,6-dimethoxy-7,8-quinolinediones (16) were synthesized by oxidative demethylation of the corresponding 2(1H-quinolinones (7) and 2-alkoxyquinolines (11) with cerium (IV) ammonium nitrate

SYNTHESIS OF EUPOMATIDINES 1,2 AND 3 AND RELATED COMPOUNDS INCLUDING IMINOQUINOLINEQUINONE STRUCTURE

Abstract Three aromatic alkaloids, eupomatidines 1 (1), 2 (2), and 3 (3), and two related compounds (27, 28) were synthesized from (6-methoxy-)1,4-naphthoquinone by hetero Diels-Alder reaction with (2-methoxy-)2-butenal dimethylhydrazone.

Synthesis of 6-Methoxy-5,8-quinolinediones and 8-Methoxy-5,6-quinolinediones Using Oxidative Demethylation with Cerium (IV) Ammonium Nitrate

6-Methoxy-5,8-quinolinediones (14-19) and 8-methoxy-5,6-quinolinediones (20-25) were synthesized by oxidative demethylation of the corresponding 5,6,8-trimethoxyquinolines (5, 7-9, 12, 13) with cerium (IV) ammonium nitrate

Synthesis of 5,8-quinoxalinediones and 5,8-quinazolinediones

5,8-Quinoxalinediones (3a-c, 12, 13), dibenzo[a,c]phenazine-10, 13-diones (5a, b), 5,8-quinazolinediones (17, 23), and 4,5,8(3H)-quinazolinetrione (21) were prepared using oxidative demethylation of the corresponding 5,8-dimethoxy compounds with cerium (IV) ammonium nitrate

Total Synthesis of Norsegoline

Abstract A tetracyclic aromatic alkaloid, norsegoline (1) was synthesized from methyl 4-amino-3-methoxybenzoate (2) and 5-methoxymethylidene-2,2-dimethyl-1,3-dioxane-4,6-dione (3) in six steps.