The [2 + 2] photocycloaddition is undisputedly the most important and most frequently used photochemical reaction. In this review, it is attempted to cover all recent aspects of [2 + 2] photocycloaddition chemistry with an emphasis on synthetically relevant, regio-, and stereoselective reactions. The review aims to comprehensively discuss relevant work, which was done in the field in the last 20 years (i.e., from 1995 to 2015). Organization of the data follows a subdivision according to mechanism and substrate classes. Cu(I) and PET (photoinduced electron transfer) catalysis are treated separately in sections 2 and 4, whereas the vast majority of photocycloaddition reactions which occur by direct excitation or sensitization are divided within section 3 into individual subsections according to the photochemically excited olefin.

http://pubs.acs.org/doi/pdf/10.1021/acs.chemrev.5b00723

Recent Advances in the Synthesis of Cyclobutanes by Olefin [2+2] Photocycloaddition Reactions

Enantiomerically pure cyclobutane derivatives and their use in organic synthesis.

Enantioselective synthesis through enzymatic asymmetrization

Lipase-catalyzed transesterification in organic solvents: Applications to the preparation of enantiomerically pure compounds

Biotransformations with Lipases

1,3‐dioxin‐4‐ones as versatile intermediates for organic synthesis

Use of 1,3-dioxin-4-ones and their related compounds in synthesis. Part 28 . Asymmetric de mayo reactions using chiral spirocyclic dioxinones

Homochiral cis -2-hydroxymethylcyclobutanols, their all cis 3-methyl, and 4-hydroxymethyl derivatives were synthesized from 1,3-dioxin-4-ones via cyclobutane ring formation by [2+2]photocycloaddition, dioxanone ring cleavage, and reduction, followed by lipase-catalyzed kinetic resolution of the resulted cyclobutanols. The chiral cyclobutanols thus obtained have been converted to the corresponding γ-lactones which are potential precursors for a series of biologically active compounds.

Regio-, stereo-, and enantioselective synthesis of cyclobutanols by means of the photoaddition of 1,3-dioxin-4-ones and lipase-catalyzed acetylation☆☆☆

Two chiral spirocyclic dioxinones (S-5 and R-5) useful in teh so-called de Mayo reaction as alternatives to β-diketones (enones) have been synthesized; they not only act as formylacetates (inactive by themselves as enones) but also display remarkable diastereofacial selectivities in photoaddition to alkenes. The sythesis of these dioxinones is described, together with a practicl one-pot synthesis of enantiomerically pure (1S, 4R)-(+)-6-formyl-2-oxabicyclo[3.3.0]oct-6-en-3-one, the key intermediated of prostaglandin synthesis, from the (6S)-spirocyclic dioxinone (S-5).

Synthesis of 1,3-Dioxin-4-ones and Their Use in Synthesis XX. : (6S, 7S, 10R)- and (6R, 7S, 10R)-7-Isopropyl-10-mythyl-4-oxo-1,5-dioxaspiro[5.5]undec-2-enes; Synthesis and Their Use in Enantiomerically Pure Corey Lactone Analogue Synthesis

Intramolecular photo[2+2] cycloaddition of dioxinones to alkene to give eight membered lactones proceeds with complete stereo- and high regioselectivities when an ester group presents as a linking unit between the acetal carbon and the double bond of the side chain. The successful separation of some dioxinones into the enantiomers indicates the method is useful for synthesis of enantiomerically pure compounds

Regio- and Stereocontrols in the Photo[2+2]cycloaddition of 1,3-Dioxin-4-ones to Alkenes. Use of an Ester Group as the Connecting Unit in the Intramolecular Variant

Yoshito Abe

Papers

1,3‐dioxin‐4‐ones as versatile intermediates for organic synthesis

Use of 1,3-dioxin-4-ones and their related compounds in synthesis. Part 28 . Asymmetric de mayo reactions using chiral spirocyclic dioxinones

Regio-, stereo-, and enantioselective synthesis of cyclobutanols by means of the photoaddition of 1,3-dioxin-4-ones and lipase-catalyzed acetylation☆☆☆

Synthesis of 1,3-Dioxin-4-ones and Their Use in Synthesis XX. : (6S, 7S, 10R)- and (6R, 7S, 10R)-7-Isopropyl-10-mythyl-4-oxo-1,5-dioxaspiro[5.5]undec-2-enes; Synthesis and Their Use in Enantiomerically Pure Corey Lactone Analogue Synthesis

Regio- and Stereocontrols in the Photo[2+2]cycloaddition of 1,3-Dioxin-4-ones to Alkenes. Use of an Ester Group as the Connecting Unit in the Intramolecular Variant