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Etudes stéréochimiques XIV. Adduits de Diels ‐ Alder en série résiniques; action des peracides et ouvertures acido‐catalysées d'époxydes
Author(s) -
Maciejewski Claude,
Gastambide Bernard
Publication year - 1977
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19770600227
Subject(s) - chemistry , epoxide , adduct , ketone , ring (chemistry) , stereochemistry , diels–alder reaction , carbon skeleton , medicinal chemistry , double bond , catalysis , organic chemistry
Studies in Stereochemistry XIV. Diels‐Alder adducts in the resin series; action of peracids and acid‐catalysed ring opening of epoxides The synthesis of Diels ‐ Alder compounds of type 2 with a 17‐nor‐13(14)‐atisène skeleton is described (cf. Schemes 1–3 ). Depending on the nature and configuration of substituents R 1 and R 2 on the carbon atoms 15 and 16, an epoxide ( 24–33 ) or a ketone ( 35–38 ) or a mixture of epoxide, ketone and lactone is obtained by the action of p ‐nitroperbenzoic acid on the double bond of these adducts (cf. Scheme 4 ). A simplified reaction scheme is suggested to explain the formation of the various products. In an acid‐catalysed reaction, the epoxides isomerize mainly into ketones. Nevertherless, in some cases, dienes ( e.g. 52 ) or hydroxy‐γ‐lactones of (13 R *, 14 S *)‐configuration ( e.g. 50 ) resulting from the opening of the epoxide ring with retention of configuration were obtained.