2 n alkyl y 1 y 2 nc o u2014 y 1 y 2 nso 2 u2014 and u2014 so 2 ny 1 y 2 wherein y 1 and y 2 can be the same or different and are independently selected from the group consisting of hydrogen alkyl aryl cycloalkyl and aralkyl u201c ring system substituent u201d may also mean a single moiety which simultaneously replaces two available hydrogens on two adjacent carbon atoms one h on each carbon on a ring system examples of such moiety are methylene dioxy ethylenedioxy u2014 c ch 3 2 u2014 and the like which form moieties such as for example u201c heterocyclyl u201d means a non aromatic saturated monocyclic or multicyclic ring system comprising about 3 to about 10 ring atoms preferably about 5 to about 10 ring atoms in which one or more of the atoms in the ring system is an element other than carbon for example nitrogen oxygen or sulfur alone or in combination there are no adjacent oxygen and or sulfur atoms present in the ring system preferred heterocyclyls contain about 5 to about 6 ring atoms the prefix aza oxa or thia before the heterocyclyl root name means that at least a nitrogen oxygen or sulfur atom respectively is present as a ring atom any u2014 nh in a heterocyclyl ring may exist protected such as for example as an u2014 n boc u2014 n cbz u2014 n tos group and the like such protections are also considered part of this invention the heterocyclyl can be optionally substituted by one or more u201c ring system substituents u201d which may be the same or different and are as defined herein the nitrogen or sulfur atom of the.