scispace - formally typeset
Search or ask a question

Showing papers on "Total synthesis published in 1969"







Journal ArticleDOI
TL;DR: In this paper, mycophenolic acid (I) was synthesized by a method adaptable to the synthesis of analogues and of possible biogenetic intermediates, and the aromatic nucleus was elaborated by a novel application of the Alder-Rickert dime synthesis.
Abstract: Mycophenolic acid (I) has been synthesized by a method adaptable to the synthesis of analogues and of possible biogenetic intermediates. The aromatic nucleus was elaborated by a novel application of the Alder- Rickert dime synthesis.

44 citations


Journal ArticleDOI
TL;DR: This is the 1st report of a total synthesis of PGE1 (prostaglandin E1), and the biological activity of the synthetic product was found to be .1% of that of the naturally-occurring P GE1 in the stimulation of smooth muscle contraction.
Abstract: 1 newly-discovered method of synthesizing PGE1 (prostaglandin E1) is explained and diagrammed chemically. Recrystallization of the synthetic product produced material identical in all respects with natural PGE1. The synthetic product showed the same infrared spectrum and chromatographic values as racemic and natural forms of PGE1. The biological activity of the synthetic product was found to be .1% of that of the naturally-occurring PGE1 in the stimulation of smooth muscle contraction. This is the 1st report of a total synthesis of PGE1. Research continues on improvements in this synthesizing method and on discovering other synthetic approaches to PGs.

42 citations


Journal ArticleDOI
TL;DR: In this paper, a total synthesis of the sesquiterpene (−)-aristolone (1) is presented, where the key step involves the cupric sulfate catalyzed intramolecular cyclization of the diazoketone 27, which produces a mixture of products, the major component of which is (±)-aristolic acid.
Abstract: A novel and efficient total synthesis of the racemic form of the sesquiterpene (−)-aristolone (1) is presented. The key step involves the cupric sulfate catalyzed intramolecular cyclization of the diazoketone 27, which produces a mixture of products, the major component of which is (±)-aristolone.

36 citations


Journal ArticleDOI
TL;DR: The first Lycopodium alkaloid annotinine in the optically active form was described in this article, where the key step in this synthesis was the photochemical addition of allene to the tricyclic vinylogous imide, which yielded the photoadduct.
Abstract: The total synthesis of the first Lycopodium alkaloid annotinine in the optically active form is described. The key step in this synthesis was the photochemical addition of allene to the tricyclic vinylogous imide (3) which yielded the photoadduct (6).

35 citations





Journal ArticleDOI
TL;DR: In this paper, a stereoselective route to 1,7-dimethylbicyclo[4.3.1]decane intermediates is described, where 2-carbethoxy-2-(3-oxobutyl)-cycloheptanones are derived via condensation with methyl vinyl ketone and cyclization.



Journal ArticleDOI
TL;DR: This work reports the first total synthesis of the simplest group of ester alkaloids containing isomeric 1-hydroxymethylpyrrolyzidines as necines, esterified by isomersic 2-isopropyl-2,3-dihydroxybutyric acids.







Journal ArticleDOI
TL;DR: Treatment of the ester of 2-(2-chloroacetamido)-2-alkenoic acid with ammonia led to the formation of 3-alkylidene-2,5-piperazinedione, and its physical constants are virtually identical with those recorded for the natural albonoursin.
Abstract: Treatment of the ester of 2-(2-chloroacetamido)-2-alkenoic acid with ammonia led to the formation of 3-alkylidene-2,5-piperazinedione. By using this method, total synthesis of albonoursin was accomplished. 2-(2-Chloroacetamido)-4-methyl-2-pentenoic acid, derived from the condensation of 4-methyl-2-oxopentanoic acid with chloroacetonitrile or the pyrolysis of 2,2-bis(2-chloroacetamido)-4-methylpentanoic acid, was converted to the ethyl ester, which was treated with ammonia to give 3-isobutylidene-2,5-piperazinedione. The piperazinedione was also synthesized by the esterification of 2-(2-aminoacetamido)-4-methylpentenoic acid, followed by a cyclization of the ester. Condensation of the piperazinedione with benzaldehyde yielded 3-benzylidene-6-isobutylidene-2,5-piperazinedione, and its physical constants are virtually identical with those recorded for the natural albonoursin.


Journal ArticleDOI
TL;DR: The total synthesis in one step of (±)-8-oxovincatine, and its reduction to a diol identical with that obtained by reduction of vincatines, confirm the structure of the latter.
Abstract: The total synthesis in one step of (±)-8-oxovincatine, and its reduction to a diol identical with that obtained by reduction of vincatine, confirm the structure of the latter.


Journal ArticleDOI
TL;DR: In this article, the Ullmann method was used to construct a benzyliso-quinoline nuclei, which was then joined by ether linkages to protected phenethylamine and phenylacetic acid units.
Abstract: Natural phaeanthine (1a), isotetrandrine (lb), and tetrandrine (1c), belonging to the oxyacanthine–berbamine series of the bisbenzylisoquinoline alkaloids, have been synthesised by a stepwise route. One of the benzyliso-quinoline nuclei was constructed initially, and joined by the Ullmann method through ether linkages to protected phenethylamine and phenylacetic acid units. The phenylacetic acid portion was activated by formation of its nitrophenyl ester and condensed with the phenethylamine unit (protected by a t-butoxycarbonyl group) to form a macrocyclic amide. The latter was converted by Bischler-Napieralski cyclisation and reduction into the desired alkaloids without formation of any structural isomers.