ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A synthesis of Methylated Epoxyhydroazulenones by Intramolecular [4 + 3] Cycloaddition of an Oxyallyl Intermediate, Generated from 1,1-Dichloro-6-(3-methyl-2-furyl)hexan-2-one(Z)-3-Methylpent-2-en-4-yn-1-ol (7) was transformed to 2-(4-chlorobutyl)-3-methylfuran (4b) and 2-(but-3-enyl)-3-methylfuran (10a) by C-alkylation and 5-exo-dig cyclization. The Grignard derivative formed from 4b gave 1,1-dichloro-6-(3-methylfur-2-yl)hexan-2-onc (1b) on reaction with dichloroacetyl chloride. This dichloromethyl ketone undergoes a base-induced cyclization to form diastereoisomeric 7-chloro-1,2,3,6,7,8a-hexahydro-4-methyl-8H-3a,6-epoxyazulen-8-ones (3bα and 3bβ) by way of an intramolecular [4+3] cycloaddition of an oxyallyl intermediate 2b. By dechlorination and hydrogenation of 3bβ, the tricyclic hydroepoxyazulenones 18 and 19 have been synthesized.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19900730530
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