Oxidation using triphosgene/DMSO

TBS-protected lactaldehyde 689 is readily prepared with high enantiomeric purity by a mild oxidation of the propanol 688 under Swem-type conditions using bis(trichloromethyl)car-bonate (triphosgene)-DMSO [203]. Triphosgene is a white crystalline solid that is easily handled, and it is a safe alternative for such other DMSO activators as phosgene or diphosgene dimer. 

The use of triphosgene as a DM SO activator has several advantages over oxalyl chloride. It is a solid that can be weighed accurately and is less susceptible to hydrolysis. Furthermore, the oxidation of yS-phenylethanols with triphosgene/DMSO gave better yields compared to oxidation with oxalyl chloride/DMSO or TFAA/ DMSO [1363]. 

Tab. 4.S1. Oxidation of alcohols using the triphosgene/DMSO system [1362],...

Table 4.52 compares the results obtained for the oxidation of alcohols with the triphosgene/DMSO reagent with those obtained using the traditional Swern method (oxalyl chloride/DMSO) [1363]. 

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