Laser flash photolysis study of photochemical ring opening of 2,3-di-2-naphthyloxiranes and resultant ylide behaviors

Journal Article · Fri Sep 21 04:00:00 EDT 1984 · J. Org. Chem.; (United States)

DOI:https://doi.org/10.1021/jo00193a003· OSTI ID:6211082

Das, P K; Griffin, G W

Under direct excitation as well as triplet energy-transfer sensitization, cis- and trans-2,3-di-2-naphthyloxiranes from short-lived triplets and carbonyl ylides. From these two oxiranes a major pathway for photogeneration of ylides involves the intermediacy of the triplet. In comparison, the triplet of cis- and trans-2,3-dimethyl-2,3-di-2-naphthyloxiranes are relatively long lived indicating their reluctance to undergo ring opening. In addition to the triplets, the transient phenomena observed upon direct excitation of these two oxiranes indicate the formation of very short-lived species (26-44 ns in benzene) absorbing at long wavelengths (500-600 nm); the latter appear to be the ylides formed from the triplet state. Adverse steric interaction in the planar structures of the ylides from 2,3-dimethyl-2,3,-di-2-naphthyloxiranes is apparently responsible for their short lifetimes and insufficient production under triplet energy-transfer sensitization. Rate constants are given for the quenching of the ylides derived from 2,3-di-2-naphthyloxiranes by dipolarophiles with enhanced reactivity being observed for the electron-deficient dipolarophiles.

• Research Organization: Univ. of Notre Dame, IN
• OSTI ID: 6211082
• Journal Information: J. Org. Chem.; (United States), Journal Name: J. Org. Chem.; (United States) Vol. 49:19; ISSN JOCEA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
CHEMICAL REACTIONS
DATA
DECOMPOSITION
ELECTROMAGNETIC RADIATION
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
INFORMATION
LASER RADIATION
NUMERICAL DATA
ORGANIC COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
RADIATIONS