@article {22579,
	title = {Guiding a divergent reaction by photochemical control: bichromatic selective access to levulinates and butenolides},
	journal = {Chemical Science},
	volume = {9},
	year = {2018},
	pages = {2041 - 6520},
	abstract = {Allylic and acrylic substrates may be efficiently transformed by a sequential bichromatic photochemical process into derivatives of levulinates or butenolides with high selectivity when phenanthrene is used as a regulator. Thus, UV-A photoinduced cross-metathesis (CM) couples the acrylic and allylic counterparts and subsequent UV-C irradiation initiates E{\textendash}Z isomerization of the carbon{\textendash}carbon double bond, followed by one of two competing processes; namely, cyclization by transesterification or a 1,5-H shift and tautomerization. Quantum chemical calculations demonstrate that intermediates are strongly blue-shifted for the cyclization while red-shifted for the 1,5-H shift reaction. Hence, delaying the double bond migration by employing UV-C absorbing phenanthrene, results in a selective novel divergent all-photochemical pathway for the synthesis of fundamental structural motifs of ubiquitous natural products.},
	url = {http://dx.doi.org/10.1039/C7SC05094A},
	author = {Sutar, Revannath~L. and Sen, Saumik and Eivgi, Or and Segalovich, Gal and Schapiro, Igor and Reany, Ofer and Lemcoff, N. Gabriel}
}
