摘要:

The second communication of this series has shown that "pithecolobine" is a family of closely related analogues represented by the general formula1. In the present paper a crude semiquantitative estimate of the individual components is achieved by a combination of vapor-phase chromatography and chemical degradation.The synthesis of the desoxypithecolobines3aand3band their tetratosylates11aandb11bis described. A comparison of these compounds with the corresponding "natural" mixtures by thin-layer chromatography in several systems, infrared, nuclear magnetic resonance, and mass spectrometry was found to support strongly the conclusions reached by the previous degradative work.

ISSN:0008-4042    

DOI:10.1139/v68-600

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Dehydrogenation of 6-methoxy-1-tetralone (1) using palladium–carbon (30%), palladium black, and quinones has been studied with a view to preparing 6-methoxy-1-naphthol (3). A novel addition product formed, during dehydrogenation of1with tetrachloro-1,2-benzoquinone, has been proved to be 2,2-(tetrachloro-o-phenylenedioxy)-3,4-dehydro-6-methoxy-1-tetralone (5). Bromination of1followed by dehydrobromination gave the naphthol3in excellent yield.

ISSN:0008-4042    

DOI:10.1139/v68-601

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The isolation and determination of the structure of luciduline, C13H21ON, an alkaloid present among the weak bases ofLycopodiumlucidulumMichx, is described. Chemical and physical evidence which suggests structure9for luciduline is presented. An X-ray diffraction study onO-p-bromobenzoyl-dihydroluciduline confirmed this hypothesis and defined the stereochemistry of the methyl group at C-8. The complete structure of luciduline, including absolute configuration, is thus represented by1. A possible mode of biosynthesis of luciduline, which is a new type ofLycopodiumalkaloid, is discussed. The mass spectra of luciduline and some of its derivatives are interpreted in terms of structure1.

ISSN:0008-4042    

DOI:10.1139/v68-602

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Some derivatives of α-cyano tétrahydro benzothiazoline-Δ2α-acetic acid and their intermediates are described. The lack of reactivity of this class of compounds and products of treatment with concentrated sulfuric acid have been studied. Assignment of configuration was based on infrared and ultraviolet spectroscopic evidence.

ISSN:0008-4042    

DOI:10.1139/v68-603

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The stereoisomeric oxides of 3-methoxycyclopentene (3and4) and the fourtrans-chlorohydrins of the same olefin (6–9) were prepared by methods resembling those used previously in the cyclohexane system. Structure proofs were more difficult than in the cyclohexanes, but served to illustrate some interesting chemistry. Product ratios in the cleavage of each of the epoxides with hydrogen chloride were used to deduce the probable conformations of the four transition states, by comparing the results with those from the cyclohexane system. An unexpected outcome of the work was the new convincing evidence obtained for the intervention of chloronium ions in the addition of "hypochlorous acid" to the olefin.

ISSN:0008-4042    

DOI:10.1139/v68-604

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

An unusual adduct is formed when 3-methylacrylophenone is treated with 2-aminothiazole. The structure of this product has been established as4a. Similar adducts have been prepared from acrylophenones with other aminoheterocycles

ISSN:0008-4042    

DOI:10.1139/v68-605

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The synthesis of 10,11-dihydro-5H-dibenzo[a,d]cycloheptene-5-carboxylic acid (2) and several derivatives of 5H-dibenzo[a,d]cycloheptene-5-carboxylic acid (1;a–c) from 5-hydroxy-10,11-dihydro-5H-dibenzo[a,d]cycloheptene-5-carboxylic acid and derivatives thereof (3;a–c) is described.Thep-toluenesulfonic acid-catalyzed elimination of water (at 110.6° in toluene) from the deuterated hydroxy ester (3b; C-10, 11d2) resulted in the incorporation of deuterium at C-5 of the olefinic ester1bwith aKH/KDof 2.76. The large magnitude of this isotope effect indicated that the reaction proceededviaa rate-determining transannular 1,5-hydride transfer from one of the benzylic positions of3bto the carbonium ion generatedalphato the methoxy-carbonyl group.

ISSN:0008-4042    

DOI:10.1139/v68-606

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The reductive dimerization of hexafluoroacetone, by reaction with sodium in a donor solvent, leads to the ionic disodium alkoxide of perfluoropinacol, a valuable intermediate for the preparation of pinacol derivatives. Cyclic alkoxides of silicon, germanium, tin, and boron are made by the reaction of this disodium alkoxide with various dihalides.Reaction with thionyl chloride, sulfuryl chloride, or sulfur(II) chloride gives perfluoropinacol sulfite, sulfate, andortho-sulfite. respectively. The stereochemistry of the last compound is discussed.

ISSN:0008-4042    

DOI:10.1139/v68-607

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Vinylation of 2,3:4,5-di-O-isopropylidene-aldehydo-D-arabinose gave a 1.3:1 mixture of 1,2:3,4-di-O-isopropylidene-6-heptene-L-gulo(andD-manno)-1,2,3,4,5-pentol (1aand2a). Successive ozonolysis and hydrolysis of the mixture of1aand2agaveD-glucose andD-mannose in a ratio of 1.4:1. Vinylation of 2,4-O-ethylidene-aldehydo-D-erythrose gave a 3.9:1 mixture of 1,3-O-ethylidene-5-hexene-L-ribo(andD-lyxo)-1,2,3,4-tetrol (3aand4a), which was degraded to formD-ribose andD-arabinose in a ratio of 4:1. The configuration of each of theC-vinyl compounds1a,2a,3a, and4awas assigned by degradation to the corresponding aldose.

ISSN:0008-4042    

DOI:10.1139/v68-608

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The synthesis and spectra (ultraviolet, infrared, and nuclear magnetic resonance) of some previously unknown 2,n-dibenzylidene and dicinnamylidenecyclanones wheren = 5–10 are described. The spectra are in accord with the expected decrease in coplanarity of the conjugated groups with increasing ring size.trans-Ring hydrogen bonding may occur in 2,10-dibenzylidenecyclodecanone but no evidence is found for this effect in the parent cyclanone.

ISSN:0008-4042    

DOI:10.1139/v68-609

出版商:NRC Research Press    

年代:1968

数据来源: NRC