Girard reagents

Girard Reagent T (2-hydrazino-N,N,N-trimethyi-2-oxo-ethanaminium chioride) [123-46-6] M 167.6, m 192 . Should be crystd from absolute EtOH (slight decomposition) when it has a slight odour, and stored in tightly stoppered containers because it is hygroscopic. 

A " -3-Ketones do not react with Girard reagents under mild conditions and thus can be separated from other reactive ketones. 

Enol esterification with acetyl chloride-acetic anhydride gives the A -trien-3-acetate, but reaction with isopropenyl acetate or with hot acetic anhydride-pyridine gives A " -trien-3-acetates. " Since A"" -3-ketones react with Girard reagents, these linear dienones can be separated from A ""-3-ketones. ... 

Decarboxylation can also be effected by reaction of the A - or A -3-keto-19-acid with Girard Reagent. ... 

The imine is exchanged away with Girard reagent T to give... 

Carboxymethyl)trimethylammonium chloride hydrazide see Girard reagent T. 

Girard Reagent T [123-46-6] M 167.6, m 192 . Crystd from absolute EtOH. 

Girard reagent T 0 (CH3)3N—Cl—ch2cnhnh2 Useful for derivatization of saturated aldehydes... 

Reference Standards. Reference standards for TLC, GC, and MS were obtained as follows. Pure abietic acid (mp 172-173 °C) was used as received. Dehydroabietic acid was prepared by oxidation of abietic acid with selenium dioxide to hydroxy abietic acid and subsequent dehydration with glacial acetic acid (11). 7-Ketodehydroabietic acid was prepared by oxidation of dehydroabietic acid with potassium permanganate and isolation of the product by way of the Girard reagent T (12). Pyroabietic acid (a mixture of dehydro- and dihydroabietic acids) was prepared by heating abietic acid with 10% palladium on charcoal to 250 °C for 1 h (13). 

The reagent is analogous to Girard reagents T and P and is prepared in the same way and used for isolation of a ketone from a mixture by conversion to a derivative extractible from ether with dilute hydrochloric acid. It is stated to be more easily purified than reagents T and P. 

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