4-N-Acylfortimicin B-1,5-carbamates

#Aminoglycoside antibiotics are a useful class of antibiotics which include streptomicins, neomycins, kanamycins, gentamicins, tobramycins, amikacin and the more recently discovered fortimicins. It is known that chemical modification of the aminoglycoside antibiotics can result in altered antibacterial and pharmacological properties of the aminoglycosides. For example, certain modifications in the getamicin and kanamycin family of antibiotics provide compounds which are less toxic than the parent antibiotics. Further, certain modifications in the gentamicin and kanamycin series have been found to alter the antibiotic spectra advantageously either by increasing the intrinsic activity or increasing the activity against resistant strains.

#While the fortimicins are a relatively new family of antibiotics, chemical modifications have been found to advantageously modify the properties of these antibiotics as well. One such modification has provided a series of 2-deoxyfortimicins, 2-deoxyfortimicin B, an intermediate for producing the antibiotic 2-deoxyfortimicin A and 2-deoxyfortimicin B derivatives. These compounds are disclosed and claimed in commonly assigned, co-pending, allowed U.S. patent application Nos. 863,006 and 863,009 (now U.S. Pat. No. 4,169,198, issued Mar. 11, 1980) both filed on Dec. 21, 1979.

#The present invention provides intermediates which are useful in the preparation of 2-deoxyfortimicin B.

#The following Examples further illustrate the present invention.

#To a stirred solution of 2.0 g of fortimicin B, 30 ml of water and 60 ml of methanol, cooled in an ice bath, is added 4.44 g of N-(benzyloxycarbonyloxy)succinimide. Stirring is continued at 0.degree. C. for 3 hours and then at room temperature for 22 hours. The major portion of the methanol is evaporated under reduced pressure and the residue is shaken with a mixture of chloroform and water. The chloroform solution is washed with water and dried over anhydrous magnesium sulfate. The chloroform is evaporated and the residue is chromatographed on silica gel. Elution with a solvent system composed of chloroform-methanol-ammonium hydroxide [234:1.4:0.1(v/v/v)] gives 1.05 g of product (1): [.alpha]sub.D.sup.25 -16.5.degree. (c 1.0, CH.sub.3 OH); IR(CDCl.sub.3)1712 and 1507 cm.sup.-1 ; NMR (CDCl.sub.3) .delta.1.03 (C.sub.6' --CH.sub.3, J.sub.6',7' =6.0 HZ), 2.32 (C.sub.4 --NCH.sub.3), 3.41 (OCH.sub.3).

#Analysis Calcd. for C.sub.39 H.sub.50 N.sub.4 O.sub.11 : C, 62.39; H, 6.71; N, 7.46 Found: C, 62.16; H, 6.76; N, 7.43