1,3-Oxathiolanes cleaved

Dithiolanes are not affected by these conditions, but a 1,3-oxathiolane is cleaved (100% yield). 

Me2CH(CH2)20NO, CH2CI2, 25°, 15 min H2O, 63-93% yield." Isoamyl nitrite cleaves aromatic dithioacetals in preference to aliphatic dithioace-tals, and dithioacetals in preference to dithioketals. It also cleaves 1,3-oxathiolanes (1 h, 65-90% yield). 

O2, hv, hexane, Ph2CO, 2-5 h, 60-80% yield. 1,3-Oxathiolanes and dithiolanes are also cleaved by these conditions. 

For(n = 3) Me2CH(CH2)20N0, CH2CI2, reflux, 2.5 h, 65% yield. 1,3-Oxathiolanes are also cleaved by isoamyl nitrite. 

The 1,3-dioxolane ring is usually inert to catalytic hydrogenation unless forcing conditions are employed. Hydrogenolysis over rhodium or palladium catalysts in the presence of an acid catalyst gives mainly hydroxy ethers as shown in equation (8). Raney nickel cleaves the oxathiolane ring (Scheme 9) and converts 1,3-benzoxathioles into phenol derivatives. 

The oxygen derivatives are stable to most oxidants the sulfur derivatives are cleaved by a wide range of oxidants. The oxygen, but not the sulfur, analogs are readily cleaved by acidic hydrolysis. Sulfur derivatives are cleaved under neutral conditions by mercury(II), silver(I), or copper(II) salts oxygen analogs are stable to those conditions. The properties of oxygen and sulfur derivatives are combined in the cyclic 1,3-oxathianes and 1,3-oxathiolanes. 

Dethioacelallzation. Dithioacetals are cleaved to the parent carbonyl compounds by reaction with this nitrite in CH2CI2 for 0.5-1.5 hours. An intermediate red color develops that probably corresponds to an intermediate S (NO)R compound. Yields range from 65 to 90%. Oxathiolanes can be cleaved in the same way. 

For in = 3) NaN02, AcCl, H2O, CH2CI2, rt, 0°C, 82-97% yield. This method also cleaves oxathiolanes. ... 

FeCl3, KI, methanol, reflux, 88-91% yield. CeCT will replace FeCH in this method to cleave dithiolanes and oxathiolanes. ... 

A case in point is cyclohexane-1,3-dione. This may be converted into a mono-dioxolan [227, 228], or into a mono-dithiolem or -oxathiolan [228]. The dioxolan is partially cleaved to the hydroxyethyl enol ether (with which it is in thermal equilibrium) by very dilute base, and it reverts to the diketone under more strongly alkaline conditions [227]. The free ketone group in these ketals can be made to react vtith various nucleophilic reagents such as phenyl lithium [228] and cyanide ion [227] and can also be subjected to the Reformatski reaction [227], but the yields in these reactions appear to be rather low. 

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