Tetrapropyl perruthenate,

Tetra-n-propylammonium perruthenate (TPAP, tetrapropyl tetraoxoruthenate) [114615-82-6] M 351.4, m 160"(dec). It is a strong oxidant and may explode on heating. It can be washed with aq n-propanol, then H2O and dried over KOH in a vac. It is stable at room temp but best stored in a refrigerator. It is sol in CH2CI2 and MeCN. [Dengel et al. Transition Met Chem 10 98 1985 Griffith et al. J Chem Soc, Chem Commun 1625 1987.] Polymer supported reagent is available commercially. 

Ruthenium compounds are perhaps the most effective catalysts for the chemoselective oxidation of primary and secondary alcohols, for they function in conjunction with almost any oxidant. A good example is the ruthenium compound tetrapropyl-ammonium perruthenate (TRAP) with oxidant NMO (Griffith, 1989). An important illustration of the use of TRAP as catalyst is in the synthesis of an intermediate in the production of the antiparasitic agent milbemycin B. 

A C-nor derivative that retained the oxetane ring was formed by oxidation of 2 -protected diol with tetrapropyl-ammonium perruthenate (TPAP), which oxidized the C-6 hydroxyl group selectively to give an unstable 7-hydroxy-6-keto derivative. This derivative then underwent a retro-aldol reaction followed by an aldol reaction to give the C-nortaxol 4.2.2.4 unfortunately the deprotected final product 4.2.2.S was unstable and could not be completely characterized (779). 

Toluene, 75-85 °C 10mol% polymer- supported perruthenate (PSP) > Toluene, 70-80 °C, 4AmS, 5mol% tetrapropyl- ammoniumperruthenate (TPAP) > Toluene, 75 °C, 10mol% TPAP-doped sol-gel ormosil )... 

Substrate Toluene, 75-85°C 10 mol% polymer supported perruthenate (PSP) Carbonyl yield Toluene, 70-80 C, 4AMS,5mol% tetrapropyl-ammo- niumperruthenate TPAP) Toluene, 75 C, 10mol%TPAP doped sol-gel omtosil ... 

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