2) By an acid catalyzed condensation of 7-guanidinoheptanamide (IX) with an equivalent amount of glyoxylspermidine (X) in the presence of glutaric acid at 60 C for 8 h. Purification of the reaction mixture gives DSG in 39% yield.

2) By an acid catalyzed condensation of 7-guanidinoheptanamide (IX) with an equivalent amount of glyoxylspermidine (X) in the presence of glutaric acid at 60 C for 8 h. Purification of the reaction mixture gives DSG in 39% yield.

1) By a stepwise conversion of spergualin to DSG in the following sequence: a) Protecting the primary and secondary amines of spergualin with N-(benzyloxycarbonyloxy)suc cinimide to form the N,N'-benzyloxycarbonyl derivative (I); b) protecting the 11-hydroxy group with 3,4-dihydro-2H-pyran to the 11-O tetrahydropyranyl derivative (II); c) converting the 1,5-hydroxy function of (II) to a 1,5-mesylate (III); d) halogenation of (III) with sodium iodide, followed by catalytic hydrogenation, to give 15-deoxy-1-O-tetrahydropyranylspergualin (IV); e) hydrolysis of (IV) with p-toluenesulfonic acid in water to yield 1,5-deoxyspergualin. The overall yield of DSG is 1.8%, based on the amount of spergualin used.

2) By an acid catalyzed condensation of 7-guanidinoheptanamide (IX) with an equivalent amount of glyoxylspermidine (X) in the presence of glutaric acid at 60 C for 8 h. Purification of the reaction mixture gives DSG in 39% yield.

2) By an acid catalyzed condensation of 7-guanidinoheptanamide (IX) with an equivalent amount of glyoxylspermidine (X) in the presence of glutaric acid at 60 C for 8 h. Purification of the reaction mixture gives DSG in 39% yield.

2) By an acid catalyzed condensation of 7-guanidinoheptanamide (IX) with an equivalent amount of glyoxylspermidine (X) in the presence of glutaric acid at 60 C for 8 h. Purification of the reaction mixture gives DSG in 39% yield.

2) By an acid catalyzed condensation of 7-guanidinoheptanamide (IX) with an equivalent amount of glyoxylspermidine (X) in the presence of glutaric acid at 60 C for 8 h. Purification of the reaction mixture gives DSG in 39% yield.

2) By an acid catalyzed condensation of 7-guanidinoheptanamide (IX) with an equivalent amount of glyoxylspermidine (X) in the presence of glutaric acid at 60 C for 8 h. Purification of the reaction mixture gives DSG in 39% yield.

2) By an acid catalyzed condensation of 7-guanidinoheptanamide (IX) with an equivalent amount of glyoxylspermidine (X) in the presence of glutaric acid at 60 C for 8 h. Purification of the reaction mixture gives DSG in 39% yield.

1) By a stepwise conversion of spergualin to DSG in the following sequence: a) Protecting the primary and secondary amines of spergualin with N-(benzyloxycarbonyloxy)suc cinimide to form the N,N'-benzyloxycarbonyl derivative (I); b) protecting the 11-hydroxy group with 3,4-dihydro-2H-pyran to the 11-O tetrahydropyranyl derivative (II); c) converting the 1,5-hydroxy function of (II) to a 1,5-mesylate (III); d) halogenation of (III) with sodium iodide, followed by catalytic hydrogenation, to give 15-deoxy-1-O-tetrahydropyranylspergualin (IV); e) hydrolysis of (IV) with p-toluenesulfonic acid in water to yield 1,5-deoxyspergualin. The overall yield of DSG is 1.8%, based on the amount of spergualin used.

2) By an acid catalyzed condensation of 7-guanidinoheptanamide (IX) with an equivalent amount of glyoxylspermidine (X) in the presence of glutaric acid at 60 C for 8 h. Purification of the reaction mixture gives DSG in 39% yield.

The synthesis of racemic 15-deoxyspergualin and tritium-labeled compound has been described: The oxidation of N-(3-hydroxypropyl)carbamic acid tert-butyl ester (I) with pyridinium chlorochromate in dichloromethane gives N-(3-oxopropyl)carbamic acid tert-butyl ester (II), which is condensed with 4-(triphenylphosphonium)butyrate (III) by means of lithium bis(trimethylsilyl)amide in THF yielding 7-(tert-butoxycarbonylamino)-4-heptenoic acid (IV). The esterification of (IV) with N-hydroxysuccinimide (V) by means of dicyclohexylcarbodiimide and 1-hydroxybenzotriazole affords the corresponding ester (VI), which is treated with ammonia in methanol giving the corresponding amide (VII). The hydrolysis of (VII) with HCl in ethyl acetate yields 7-amino-4-heptenamide (VIII), which is treated with 3,5-dimethylpyrazole-1-carboxamidine (IX) and K2CO3 in methanol affording 7-guanidino-4-heptenamide (X). The reduction of (X) gives 7-guanidinoheptanamide (XI), which is finally condensed with glyoxylspermidine (XII) by means of glutaric acid in hot water. The tritium-labeled compound can also be obtained in the same way by performing the reduction of heptenamide (X) with tritium gas.

The synthesis of [14C]-labeled 15-deoxyspergualin trihydrochloride has been reported: The condensation of [14C]-labeled S-methylisothiourea (I) with 7-aminoheptanoic acid (II) by means of NaOH in water gives 7-guanidinoheptanoic acid (III), which is treated with Dowex 50W resin (H+ form) in refluxing methanol yielding the corresponding methyl ester (IV). The reaction of (IV) with concentrated NH4OH affords the amide (V), which is finally condensed with glyoxyloxyspermidine (VI) by means of glutaric acid in hot water (60 C), and purified by chromatography over Sephadex CM-25 (Na+ form).

A new synthesis of (-)-15-deoxyspergualin has been reported: The hydrolysis of 7-bromoheptanenitrile (I) with HCl gives the corresponding amide (II), which by reaction with sodium azide yields 7-azidoheptanamide (III). The condensation of (III) with 2-hydroxy-2-methoxyacetic acid methyl ester (IV) affords the alpha-hydroxyglycine derivative (V), which is condensed with 1(S)-(2-naphthyl)ethanol (VI) by means of SO2Cl2 and triethylamine in dichloromethane providing the diastereomeric mixture (VII). Hydrolysis of the ester group of (VII) with NaOH yields the corresponding free acid (VIII), which is condensed with the diprotected triamine (IX) by means of DCC and HOBt in dichloromethane affording a diastereomeric mixture of diamides. This mixture is separated by flash chromatography giving the desired diastereomer (X). The condensation of (X) with the protected isothiourea (XI) by means of triphenylphosphine in THF/water provides the proteted guanidino derivative (XII), which is finally deprotected by hydrogenation with H2 over Pd/C in methanol/acetic acid.

The hydrolysis of 7-bromoheptanenitrile (I) with HCl gives the corresponding amide (II), which is treated with Na-N3 in hot DMSO to yield 7-azidoheptanamide (III) (1). The condensation of (III) with 2-hydroxy-2-methoxyacetic acid methyl ester (IV) in hot dichloromethane affords the alpha-hydroxyglycine (V), which is treated with SOCl2 in the same solvent to provide the alpha-chloroglycine (VI). The reaction of (VI) with benzyl alcohol and TEA in dichloromethane furnishes the benzyloxy derivative (VII), which is hydrolyzed at the ester group by means of NaOH in DME to give the carboxylic acid (VIII). The condensation of (VIII) with N1,N4-bis(benzyloxycarbonyl)spermidine (IX) by means of DCC and HOBt in dichloromethane yields the corresponding amide (X), which is reduced at the terminal azido group by means of PPh3 in THF/water, affording the expected primary amine (XI). The condensation of (XI) with the protected isothiourea (XII) in THF affords the protected guanidine derivative (XIII), which is finally deprotected by hydrogenolysis with H2 over Pd(OH)2 in methanol/acetic acid to provide the target compound.

2) By an acid catalyzed condensation of 7-guanidinoheptanamide (IX) with an equivalent amount of glyoxylspermidine (X) in the presence of glutaric acid at 60 C for 8 h. Purification of the reaction mixture gives DSG in 39% yield.

1) By a stepwise conversion of spergualin to DSG in the following sequence: a) Protecting the primary and secondary amines of spergualin with N-(benzyloxycarbonyloxy)suc cinimide to form the N,N'-benzyloxycarbonyl derivative (I); b) protecting the 11-hydroxy group with 3,4-dihydro-2H-pyran to the 11-O tetrahydropyranyl derivative (II); c) converting the 1,5-hydroxy function of (II) to a 1,5-mesylate (III); d) halogenation of (III) with sodium iodide, followed by catalytic hydrogenation, to give 15-deoxy-1-O-tetrahydropyranylspergualin (IV); e) hydrolysis of (IV) with p-toluenesulfonic acid in water to yield 1,5-deoxyspergualin. The overall yield of DSG is 1.8%, based on the amount of spergualin used.

2) By an acid catalyzed condensation of 7-guanidinoheptanamide (IX) with an equivalent amount of glyoxylspermidine (X) in the presence of glutaric acid at 60 C for 8 h. Purification of the reaction mixture gives DSG in 39% yield.

The hydrolysis of 7-bromoheptanenitrile (I) with HCl gives the corresponding amide (II), which is treated with Na-N3 in hot DMSO to yield 7-azidoheptanamide (III) (1). The condensation of (III) with 2-hydroxy-2-methoxyacetic acid methyl ester (IV) in hot dichloromethane affords the alpha-hydroxyglycine (V), which is treated with SOCl2 in the same solvent to provide the alpha-chloroglycine (VI). The reaction of (VI) with benzyl alcohol and TEA in dichloromethane furnishes the benzyloxy derivative (VII), which is hydrolyzed at the ester group by means of NaOH in DME to give the carboxylic acid (VIII). The condensation of (VIII) with N1,N4-bis(benzyloxycarbonyl)spermidine (IX) by means of DCC and HOBt in dichloromethane yields the corresponding amide (X), which is reduced at the terminal azido group by means of PPh3 in THF/water, affording the expected primary amine (XI). The condensation of (XI) with the protected isothiourea (XII) in THF affords the protected guanidine derivative (XIII), which is finally deprotected by hydrogenolysis with H2 over Pd(OH)2 in methanol/acetic acid to provide the target compound.