PROCESS FOR PREPARING ENANTIOMERICALLY ENRICHED JAK INHIBITORS

1 . A process for preparing a compound of Formula I:

or a salt thereof,

the process comprising reacting a compound of Formula II′:

or a salt thereof, in the presence of an acid such that a compound of Formula I is formed;

wherein in Formula I and Formula II′,

Y 1 is hydrogen or deuterium;

each Y 2 is the same and is hydrogen or deuterium;

each Y 3 is the same and is hydrogen or deuterium;

and in Formula II′,

each R 1 ′ is C 1 -C 10 alkyl, or C 2 -C 10 alkenyl, or the two R 1 ′s, taken together with the oxygen atoms to which they are attached, form a 5-7-membered heterocyclic ring which may optionally be substituted; and

each R 6 is independently selected from H and a protecting group.

2 . The process of claim 1 , wherein the acid is selected from trifluoroacetic acid (TFA), phosphoric acid, hydrochloric acid, or a combination thereof.

3 - 16 . (canceled)

17 . A process for preparing a compound of Formula III′:

or a salt thereof;

the process comprising reacting a compound of Formula VIII′:

or a salt thereof;

with a compound of Formula VII:

or a salt thereof;

in the presence of a base, such that a compound of Formula III, or a salt thereof, is formed;

wherein:

Y 1 is hydrogen or deuterium;

each Y 2 is the same and is hydrogen or deuterium;

each Y 3 is the same and is hydrogen or deuterium;

each R 1 ′ is C 1 -C 10 alkyl, or C 2 -C 10 alkenyl, or the two R 1 ′s, taken together with the oxygen atoms to which they are attached, form a 5-7-membered heterocyclic ring which may optionally be substituted; and

each R 6 is independently selected from H and a protecting group.

18 . The process of claim 17 , wherein the base is selected from tripotassium phosphate, hydrated tripotassium phosphate and potassium carbonate.

19 - 24 . (canceled)

25 . The process according to claim 1 , wherein the protecting group is selected from t-butoxycarbonyl, triflyl, trifluoroacetyl, and trityl.

26 . The process according to claim 1 , wherein both R 6 are H.

27 . The process according to claim 1 , wherein both R 1 are methyl.

28 . The process according to claim 1 , wherein Y 1 is hydrogen and each of Y 2 and Y 3 is deuterium.

29 . The process according to claim 1 , wherein each of Y 1 , Y 2 , and Y 3 is hydrogen.

30 . The process according to claim 1 , wherein the deuterium incorporation at each position designated as deuterium is at least 90%.

31 . The process according to claim 1 , wherein the deuterium incorporation at each position designated as deuterium is at least 95%.

32 . The process according to claim 1 , wherein the deuterium incorporation at each position designated as deuterium is at least 97%.

33 . (canceled)

34 . A compound represented by any of the following structures:

or a salt thereof.

35 - 47 . (canceled)

48 . The compound according to claim 34 , wherein the deuterium incorporation at each position designated as deuterium is at least 90%.

49 . The compound according to claim 34 , wherein the deuterium incorporation at each position designated as deuterium is at least 95%.

50 . The compound according to claim 34 , wherein the deuterium incorporation at each position designated as deuterium is at least 97%.