Mattox rearrangement

The reaction is generally carried out in an alcoholic solvent, resulting in formation of the acetal the general scheme is called the Mattox rearrangement, and the yields are usually high. If a nonalcoholic solvent and acid are used, the aldehyde is obtained directly, but in lower yield. However, the use of zinc acetate as catalyst instead of an acid permits isolation of the aldehyde in ca. 50 % yield. Tire use of refluxing acetic acid alone... 

A-ring unsaturated ketones and the sensitive 11 j5-hydroxyl group will survive conditions of the Mattox rearrangement. 

The Porter-Silber reaction, diagnostic for the dihydroxyacetone side-chain, depends upon prior Mattox rearrangement. " ... 

The Mattox Rearrangement Cortisone acetate (10 g) is suspended in dry methanolic hydrogen chloride (400 ml, 0.52 N). After 10 min of agitation the material dissolves completely to give a yellow solution which is then kept at 25° for 48 hr. Sodium acetate (22 g) in water (60 ml) is added and the solvent removed in vacuo to a volume of 75 ml. Water (100 ml) is added, and... 

Maleic anhydride, 348 Manganese dioxide, 156, 426, 428 Mattox rearrangement, 216 2/8-Mesyloxy-3a-azido-5a-cholestane, 28 3 -Methoxy-17a-aminomethy lestra-1,3,... 

A A -S-ketone will survive this treatment. By contrast, treatment of a 17a, 21-dihydroxy-20-one with zinc-acetic acid produces a 21-acetoxy-20-ketone, probably via a Mattox-Kendall rearrangement (see below)... 

---