2- Butene Paterno-Buchi reaction with

A clear evidence for a long-lived intermediate came from investigations of the stereoselectivity of the Paterno-Buchi reaction with cis and trans 2-butene as substrates, when acetone [52] or benzaldehyde [53] was used as carbonyl addends, complete stereo-randomization was observed. Acetelde-hyde and 2-naphthaldehyde showed stereoselective addition reactions which accounts for the singlet mi as the reactive state [43]. Fleming and Gao... 

The first report concerning an asymmetric Paterno-Buchi reaction with a chiral carbonyl component was reported in 1979 by Gotthardt and Lenz [128]. The photocycloaddition of the enantiomerically pure menthyl ester of phenylglyoxylic acid 133 with 2,3-dimethyl-2-butene gave the oxetane 134 with a diastereomeric excess of only 37% (Sch. 45). 

Yang, N. C., Kimura, M., and Eisenhardt, W., Paterno-Buchi reactions of aromatic aldehydes with 2-butenes and their implication on the rate of intersystem crossing of aromatic aldehydes, /. Am. Chem. Soc., 95, 5058, 1973. 

The photocycloaddition of a carbonyl compound to an olefin with the formation of an oxetane 3 was first observed by Paterno and Chieffi in 1909.1 They reported obtaining a compound in good yield from the irradiation of benzophenone in a petroleum mixture rich in 2-methyl-2-butene, for which they proposed the oxetane structure. Although Paterno and Chieffi had suggested the correct structure, it was not until 1954 that Buchi and his collaborators reinvestigated this reaction and... 

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