Cyclic oxygenates

XVII XVII, 1st 1933 2359-2503 One, Cyclic Oxygen (S, Se or Te). Stem nuclei Furan, 27. Thiophene, 29. 

XIX XIX, 1st 1934 2666-3031 Two Cyclic Oxygens. Stem nuclei Dioxan, 1. Thianthrene,... 

Supplement 1952 2666-3031 Carbonyl compounds Ethylene carbonate, 100. Piperonal, 116. Thioindigo, 177. Fluorescein, 222. Carboxylic acids Piperonylic acid, 269. Amines, 328. Three Cyclic Oxygens, 381. Four Cyclic Oxygens, 433. Fiite Cyclic Oxygens, 459.. . . ... 

In general, azoles containing a cyclic oxygen atom are readily reduced, those with cyclic sulfur with more difficulty, and wholly nitrogenous azotes not at all. 

Compounds with one cyclic nitrogen and one cyclic oxygen atom. 

Compounds with one cyclic nitrogen and three cyclic oxygen atoms, etc. Compounds with two cyclic nitrogen and one cyclic oxygen atom. 

Compounds with two cyclic nitrogen and two cyclic oxygen atoms. 

XXVII XXVII, 1st i Supplement 1937 4199-4720 One Cyclic Oxygen and One Cyclic Nitrogen. 

One interesting difference between vinyl compounds and cyclic oxygen compounds is that with some of the latter, e.g., tetrahydrofuran, all kinds of chain-breaking reactions... 

There are many studies of the mechanism and kinetics of the polymerisation of cyclic oxygen compounds, but only relatively few of these are concerned with cyclic formals. In the present paper I will review this field, and I hope to show that formals have some special characteristics which distinguish their polymerisations from those of other cyclic oxygen compounds. Since it is not possible to deal with all aspects of this group of reactions in one lecture, I will concentrate attention on questions of chemistry and mechanism, and I will not deal with other aspects, such as the thermodynamics and kinetics of these polymerisations. Most of the published work has been done with 1,3-dioxolan (I) and there are only very few papers on any other cyclic formals, although the patent literature on the homo- and copolymerisation of (I) and other cyclic formals is quite extensive. 

Highly efficient C-H insertion adjacent to oxygen atoms to generate /9-hydroxy esters has been demonstrated [130, 143, 144]. Reactions with cyclic oxygenated systems have not been extensively explored with these carbenoids and only the reaction with tetrahy-drofuran has been reported [130]. The major sy -diastereomer 218 from the reaction of methyl phenyldiazoacetate with tetrahydrofuran at -50 °C was obtained in 67% yield with 97% enantiomeric excess (Eq. 29). 

XVII XVII, 1st Supplement (combined with Volumes XVIII and XIX) XVII, 2nd Supplement 1933 1934 1952 2359-2503 2359-3031 2359-2503 One Cyclic Oxygen (S, Se or Te). Stem nuclei Furan, 27. Thiophene, 29. Hydroxy compounds Furfuryl alcohol, 112. Carbonyl compounds Butyrolactone, 234. Furfural, 272. 2-Aeetyl-thio-phene, 287. Xanthone, 355. Succinic anhydride, 404. Phthalic anhydride, 469. 

XVIII XVIII, 1st 1934 2504-2665 One Cyclic Oxygen (continued). Carbonyl compounds (continued) ... 

The C-N bond formation takes place exclusively at the anomeric center because of stereoelectronical effects of the endo cyclic oxygen. 

Again, an entirely different product geometry has been found in the reaction of phenyldicyanophosphane with HFA. X-Ray structure analysis of 80 shows the two cyclic oxygen atoms to occupy the axial positions (241). 

---