Synthesis and transformations of (±)-trans-4aβ(H), saα(H)-octahydro-4α,7β-dimethyl-2H-1-benzopyran-2-one

Autor: Y. S. Sanghvi, A. S. Rao
Rok vydání: 1982
Předmět:
Zdroj: Journal of Heterocyclic Chemistry. 19:1377-1380
ISSN: 1943-5193
0022-152X
DOI: 10.1002/jhet.5570190624
Popis: Hydrogenation of 4,7-dimethylcoumarin (1) in alkaline medium has been shown to furnish a mixture of (±)-trans-4aβ(H),8aα(H)-octahydro-4α,7β-dimethyl-2H-1-benzopyran-2-one (2), (±)-trans-4aβ(H),8aα(H)-octahydro-4α,7α-dimethyl-2H-1-benzopyran-2-one (3) and (±)-cis-4aα(H),8aα(H)-octahydro-4α,7α-dimethyl-2H-1-benzopyran-2-one (4) in 40:25:35:ratio, respectively. The stereochemistry of the major hydrogenation product 2, has been established by transforming it to p-menthane derivatives e.g. (±)-2 (R)-[2′(R)hydroxy-4′(R) methylcyclohex-(1′S)-yl]propan-1-ol (20) and (±)-trans-3α,6β-dimethyl-3aβ(H),7aα(H)-octahydrobenzofuran (12). Starting from a mixture of lactones 2, 3 and 4, lactone 3 has been obtained in pure state employing a sequence of reactions.
Databáze: OpenAIRE
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