𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Photoannelation Reactions of 3-(Alk-1-ynyl)cyclohept-2-en-1-ones

✍ Scribed by M. Robert J. Vallée; Inga Inhülsen; Paul Margaretha

Publisher
John Wiley and Sons
Year
2010
Tongue
German
Weight
173 KB
Volume
93
Category
Article
ISSN
0018-019X

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

Irradiation (350 nm) of the newly synthesized 3‐(alk‐1‐ynyl)cyclohept‐2‐en‐1‐ones 1 and 2 leads to the selective formation of tricyclic head‐to‐head dimers. In the presence of 2,3‐dimethylbuta‐1,3‐diene, the (monocyclic) enone 1 affords trans‐fused 7‐alkynyl‐bicyclo[5.2.0]nonan‐2‐ones as major photoproducts, whereas photocycloaddition of benzocyclohept‐5‐en‐7‐one 2 to the same diene gives preferentially the eight‐membered cyclic allene 16 via ‘end‐to‐end’ cyclization of the intermediate allyl‐propargyl biradical 22. On contact with acid, cycloocta‐1,2,5‐triene 16 isomerizes to cycloocta‐1,3,5‐triene 18.

📜 SIMILAR VOLUMES

Photocycloaddition Reactions of 2-(Alk-3
Photocycloaddition Reactions of 2-(Alk-3-en-1-ynyl)cyclohex-2-enones
✍ Janne Möbius; Paul Margaretha 📂 Article 📅 2008 🏛 John Wiley and Sons 🌐 German ⚖ 143 KB

## Abstract The newly synthesized 2‐(alk‐3‐en‐1‐ynyl)cyclohex‐2‐enones **4** undergo photodimerization (chemo‐ and regio‐)selectively at the exocyclic CC bond to give diastereoisomeric mixtures of 1,2‐dialkynyl‐1,2‐dimethylcyclobutanes. On irradiation of **4** in the presence of 2‐chloroacrylonitr

ChemInform Abstract: Photocycloaddition
ChemInform Abstract: Photocycloaddition Reactions of 2-(Alk-3-en-1-ynyl)cyclohex-2-enones.
✍ Janne Moebius; Paul Margaretha 📂 Article 📅 2009 🏛 John Wiley and Sons ⚖ 27 KB 👁 1 views

## Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable v

Photocycloaddition Reactions of 5,5-Dime
Photocycloaddition Reactions of 5,5-Dimethyl-3-(3-methylbut-3-en-1-ynyl)cyclohex-2-en-1-one
✍ Inga Inhülsen; Jürgen Kopf; Paul Margaretha 📂 Article 📅 2008 🏛 John Wiley and Sons 🌐 German ⚖ 197 KB

## Abstract The title cyclohexenone **1d** undergoes photodimerization selectively at the exocyclic CC bond to give a 1 : 1 mixture of 1,2‐dialkynyl‐1,2‐dimethylcyclobutanes **6** and **7**. On irradiation in the presence of 2,3‐dimethylbuta‐1,3‐diene, **1d** affords bicyclo[8.4.0]tetradeca‐1,2,3,

Photoisomerization of 2H,6H-Thiin-3-ones
Photoisomerization of 2H,6H-Thiin-3-ones to 2-(Alk-1-enyl)thietan-3-ones
✍ Erhan Er; Paul Margaretha 📂 Article 📅 1992 🏛 John Wiley and Sons 🌐 German ⚖ 298 KB

## Abstract Reaction of 3‐bromo‐3‐methylbutan‐2‐one (1) with mercapto‐esters 2 affords 5‐oxo‐3‐thiahexanoates 3 which cyclize to thiane‐3,5‐diones 4. Conversion of these dicarbonyl compounds to their ethyl enol ethers 5–7 followed by reduction with LiAlH~4~ gives 2__H__,6__H__‐thiin‐3‐ones 8–10. On