Harvesting the Strain Installed by a Paternò−Büchi Step in a Synthetically Useful Way: High-Yielding Photoprotolytic Oxametathesis in Polycyclic Systems

Abstract

High-yielding one-pot photoinduced transformation of readily available endoaroyl and heteroaroyl Diels-Alder adducts into novel polycyclic aldehydes or their hemiacetals, decorated by carbo- and heterocyclic pendants, is described.

Syntheses and Applications of Functionalized Bicyclo[3.2.1]octanes: Thirteen Years of Progress

“…198 The oxametathesis reaction of Paterno−Buchi [2 + 2]-photoadducts 360 described by Valiulin and Kutateladze also provides an interesting synthetic route to various aldehydesubstituted polycyclic structures. 203 For example, the reactions of 360 with a trace amount of HCl or BF 3 ·OEt 2 provided cleanly the rearranged bicyclo[3.2.1]octenes 361 in good to excellent yields (Scheme 122).…”

Double-Tandem [4π+2π]·[2π+2π]·[4π+2π]·[2π+2π] Synthetic Sequence with Photoprotolytic Oxametathesis and Photoepoxidation in the Chromone Series

“…We, on the other hand, have recently developed a high yielding tandem ground state – excited state [4 π +2 π ]•[2 π +2 π ] modular approach, where the photochemical Paternò-Büchi step in a strained polycycle is accompanied by an acid-catalyzed fragmentation of the oxetane E into an alternative carbonyl-alkene pair, Scheme 2 7…”

FeCl3‐Catalyzed Ring‐Closing Carbonyl–Olefin Metathesis

“…[4] Stoichiometric Lewis-acid-promoted reactions of RCCOM have also been disclosed, but only af ew of carbocycles could be achieved. [4] Stoichiometric Lewis-acid-promoted reactions of RCCOM have also been disclosed, but only af ew of carbocycles could be achieved.…”

“…[7] However, in our reaction, the formation of 9 supports as tepwise mechanism. [4,5,7,14] [a] Reaction conditions: 6 (0.1 mmol), FeCl 3 (0.02 mmol), allyltrimethylsilane (0.5 mmol), DCE (1.0 mL), 0 8 8C, 24 h. n.r. [5a] FeCl 3 coordinates with the carbonyl group of the substrate to generate the intermediate A.I ntramolecular electrophilic cyclization of A affords the zwitterionic intermediates B and C, [12] and C is an onproductive intermediate.S ubsequently, the fused oxetane intermediate D is formed from B.W e rationalized that this stepwise process is reversible, [13] and this proposal is partially supported by the generation of 9 as depicted in Equation 3.…”