Showing papers by "Keiichiro Fukumoto published in 1995"
29 citations
TL;DR: The iodonium ion mediated ring expansion of the olefinic cyclobutanols 19, 20, and 22 gave the mixture of iodoalkylated cyclopentanones 27a-c and 28a−c, respectively as mentioned in this paper.
12 citations
TL;DR: A successful design for the construction of C 20 gibberellin framework has been described in this article, where the key features of the synthesis are as follows: (a) Pd 2+ -promoted cycloalkenylation reaction ( 6 → 5 ) and (b) intramolecular Diels-Alder reaction ( 4 → 3 ).
10 citations
TL;DR: In this paper, the induced diastereoselectivity of the intramolecular Diels-Alder reaction of the trifluoromethyl substituted olefinic o -quinodimethanes 10, 11, and 21 a g, generated in situ by the thermolysis of the corresponding benzocyclobutenes 6, 7, and 20a g respectively, was investigated experimentally and theoretically.
9 citations
TL;DR: Indirect electroreductive cyclization of η-bromo-α,β-unsaturated esters 1-6 using Co(III) or Ni(II) complex as an electron-transfer catalyst provided the six membered compounds 7-12, which are useful synthetic intermediates of several indole and ipecac alkaloids as mentioned in this paper.
Abstract: Indirect electroreductive cyclization of η-bromo-α,β-unsaturated esters 1-6 using Co(III) or Ni(II) complex as an electron-transfer catalyst provided the six membered compounds 7-12, which are useful synthetic intermediates of several indole and ipecac alkaloids
7 citations
7 citations
6 citations
3 citations
TL;DR: A successful design for the construction of C 20 gibberellin framework has been described in this paper, where the key features of the synthesis are as follows: (a) Pd 2+ -promoted cycloalkenylation reaction ( 6 → 5 ) and (b) intramolecular Diels-Alder reaction ( 4 → 3 ).
Abstract: A successful design for the construction of C 20 gibberellin framework has been described. The key features of the synthesis are as follows: (a) Pd 2+ -promoted cycloalkenylation reaction ( 6 → 5 ) and (b) intramolecular Diels-Alder reaction ( 4 → 3 ).
TL;DR: In this article, the optically pure sulfone was converted into the olefinic cyclobutanone, which was then transformed into the ketonic lactone via the oleinic lactone.
Abstract: The optically pure sulfone 15, prepared by the tandem asymmetric epoxidation and 1,2-rearrangement of the cyclopropylideneethanol 11 as a key step, was converted into the olefinic cyclobutanone 20 which was then transformed into the ketonic lactone 22 via the olefinic lactone 21. This constitutes the formal total synthesis of (−)-mesembrine (1).
TL;DR: Indirect electroreductive cyclization of η-bromo-α,β-unsaturated esters 1-6 using Co(III) or Ni(II) complex as an electron-transfer catalyst provided the six membered compounds 7-12, which are useful synthetic intermediates of several indole and ipecac alkaloids as discussed by the authors.
Abstract: Indirect electroreductive cyclization of η-bromo-α,β-unsaturated esters 1-6 using Co(III) or Ni(II) complex as an electron-transfer catalyst provided the six membered compounds 7-12, which are useful synthetic intermediates of several indole and ipecac alkaloids
TL;DR: Optically active des-A C-13 ethyl steroids 17∼20 have been synthesized by thermolysis of the optically active alkenic benzocyclobutene 14 as a key process as discussed by the authors.
Abstract: Optically active des-A C-13 ethyl steroids 17∼20 have been synthesized by thermolysis of the optically active alkenic benzocyclobutene 14 as a key process.
TL;DR: In this article, an efficient formal total synthesis of antiviral and antitumor tetracyclic diterpene aphidicolin has been developed using an intramolecular Heck reaction (3→4 ) and an intramerolecular Diels-Alder reaction (7→8 ) for the key step of the sequence.
Abstract: An expeditious and efficient formal total synthesis of antiviral and antitumor tetracyclic diterpene aphidicolin has been developed. An intramolecular Heck reaction ( 3→4 ) and an intramolecular Diels-Alder reaction ( 7→8 ) were utilized for the key step of the sequence.