Approaches to the synthesis of triterpenoids. IV. The ABC + E ring approach to the pentacyclic triterpene skeleton. Synthesis of a pentacyclic compound suitable for triterpene synthesis
العنوان: | Approaches to the synthesis of triterpenoids. IV. The ABC + E ring approach to the pentacyclic triterpene skeleton. Synthesis of a pentacyclic compound suitable for triterpene synthesis |
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المؤلفون: | John W. Hooper, Richard Pike, John W. ApSimon, Carol P. Huber, Satyanand Badripersaud, Michael L. Post, George Birnbaum |
المصدر: | Canadian Journal of Chemistry. 56:2139-2149 |
بيانات النشر: | Canadian Science Publishing, 1978. |
سنة النشر: | 1978 |
مصطلحات موضوعية: | chemistry.chemical_classification, Triterpenoid, Triterpene, chemistry, Stereochemistry, Organic Chemistry, Diastereomer, Organic chemistry, General Chemistry, Skeleton (category theory), Catalysis |
الوصف: | Studies on the ABC + E ring construction of the pentacyclic triterpene skeleton are described. Acid-catalysed cyclisation of the mixture of diastereoisomers 11 led to preferential cyclisation of one isomer to 10-methoxy-2,2,4aβ,6aβ, 12bβ -pentamethyl-1,2,3,4,4a,5,6,6a, 6bα,7,8,12b,13,14-tetradecahydro-1-picenone (12). An X-ray analysis was performed on this compound which crystallizes in the monoclinic space group P2/c. There are four molecules in the unit cell which has dimensions a = 6.456(2), b = 42.518(6), c = 8.519(2) Å, β = 100.92(3)°. The structure was solved by direct methods and refined by block-diagonal least-squares to a final R value of 0.042 for all 3234 observed reflections. The molecular structure found by X-ray diffraction confirms the stereochemical reasoning used in the synthetic steps. |
تدمد: | 1480-3291 0008-4042 |
URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::1bdf298afba25a0cec1ac840c27b3307 https://doi.org/10.1139/v78-350 |
حقوق: | OPEN |
رقم الأكسشن: | edsair.doi...........1bdf298afba25a0cec1ac840c27b3307 |
قاعدة البيانات: | OpenAIRE |
تدمد: | 14803291 00084042 |
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