Polonovski-type reaction

Utilizing Wenkert s cyclization process, a number of new approaches have been elaborated for the synthesis of simple indolo[2,3-a]quinolizine derivatives. For example, treatment of JV-[2-(indol-3-yl)ethyl]piperidine (V-oxide (134) with trifluoroacetic anhydride gave piperideinium intermediate 135 in a Polonovski-type reaction, which could be cyclized in acidic medium to ( )-l (101). 

The Polonovski-type reaction of the tetrahydroisoquinoline Al-oxide 51 with an O-TBDPS ketene acetal, which activates the iV-oxide, produces an intermediate iminium ion that reacts with 0-TMS ketene acetal resulting in alkylation at the 1-position <97JOC8268>. 

The reaction of substituted aminomethyl radicals with benzoyl, acetyl or cyclohexanesulfonylacetyl peroxides involves at least partially the free radical process of Scheme 26 (Horner and Schwenk, 1944 Homer and Betzel, 1953 Horner and Anders, 1962 Walling and Indictor, 1958 Hrabak and Lokaj, 1970). The same products are also formed by the ionic Polonovski-type reaction involving the intermediate PhN(Me)202CPh PhCOJ which decomposes to PhN(Me)CH202CPh via PhI (Me)(02CPh)CH2. ... 

The acylation of 1,4-benzodiazepine 4-oxides, e.g. (230), leads to a Polonovski-type rearrangement giving (231) and provides a useful way of functionalizing the 3-position. Treatment of (230) with p-toluenesulfonyl chloride gives the quinoxalone (233) via a Beckmann type of rearrangement (72JHC747, p. 755) and similar rearrangements have been observed in the reactions of 4-hydroxy derivatives with thionyl chloride or phosphorus oxychloride. 

Grierson, D. S., Husson, H.-P. Polonovski- and Pummerer-type reactions and the Nef reaction, in Comp. Org. Synth, (eds. Trost, B. 

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