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Synthesis of α‐carboxy‐γ‐butyrolactones by rearrangement of capto‐dative cyclopropanes on silica surfaces
Author(s) -
Alonso Miguel E.,
Gómez Matilde,
De Sierraalta Sarah P.,
Patricia Jano S.
Publication year - 1982
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570190230
Subject(s) - cyclopropane , chemistry , vicinal , alkyl , ring (chemistry) , medicinal chemistry , stereochemistry , hydrolysis , organic chemistry
The rearrangement of some cyclopropanes featuring electron‐withdrawing and electron releasing substitu‐ents on vicinal carbons of the trimethylene ring to α‐carboxy‐γ‐lactones upon contact with silica gel at room temperature has been discovered. One or two alkyl ester groups were chosen as electron attractor substitu‐ents while one or two cyclopropyl units were used for the release of electron density. It was observed that the lactone forming process is strongly dependent upon these substituents to the extent that only two ester groups and at least one cyclopropane will confer enough vulnerability to the tetra‐substituted cyclopropane for the rearrangement to take place. A comparative study of the lactonization by means of contact with silica and alkaline hydrolysis was performed and some mechanistic considerations are put forth.