Enamines reaction with thiirene

The ring-opening process leading to 164 (route a) is analogous to that which has been demonstrated to follow the cycloadditions of tosyl azide to certain enamines . Similar results have been reported for the reaction of 2,3-diphenylcyclopropenone with 2-diazopropane . Other 1,3-dipolar cycloadditions with thiirene dioxides could also be affected (see below). 

Reaction of thiirene 1,1-dioxides with enamines ) -Amino-a,) -bis(ethylene)sulfones... 

The majority of the intramolecular (2 + 2)-cycloreversions of hetero-bicyclic compounds proceed via ring opening of an annulated cyclobutene or azetine ring. Only in one instance has the same reaction of a cyclobutane ring been proposed as an intermediate step, viz., in the reaction of a thiirene 1,1-dioxide with enamines (Section II,B).33... 

The reaction of 2,3-diphenyl- or 2,3-bis-(4-chlorophenyl)-thiiren 1,1-dioxide with enamines R R C=CR NR 2 yields a variety of heterocyclic compounds, including medium- and large-ring sulphur heterocycles, via decomposition of a bicyclic thiiran dioxide intermediate (26). Treatment of these thiiran dioxides with 2-pyrrolidinyl- or 2-piperidinyl-2-norbornene gave adducts which possessed antifertility activity. The reaction of 2,3-diphenylthiiren 1,1-dioxide with several meso-ionic compounds, e.g. (27), gave 2,3,5,6-tetraphenyl-4 -l,4-thiazine 1,1-dioxides by loss of carbon dioxide from the intermediate adduct (28). ... 

The reaction of 2,3-diphenylthiiren 1,1-dioxide (8) with enamines derived from cyclic ketones gives rise to ring-enlargement products such as (9), which contain the divinyl sulphone unit e.g. the reaction of l-(l-cyclohexen-l-yl)-pyrrolidine (10) with the above thiiren gave (9 n = 1), in 86% yield. The ten-and thirteen- to fifteen-membered-ring analogues were also prepared from the... 

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