Chemistry of the Neomycins. V. Differentiation of the Neomycin Complex. Identity of Framycetin and Neomycin B. Compounds Obtained from Methyl Neobiosaminide B

Hypersensitivity to Antibiotics

“…We could definitely ascertain th a t 11 patients had never been treated with fram ycetin. This frequent combination of neomycin and fram ycetin sensitivity is not surprising, as it was re cently dem onstrated by means of paper chrom atography [12], th at framycetin and neomycin B, which is a part of the neomycin complex, are nearly identical.…”

Ophthalmological Preparations

“…Neomycin B is isolated from the mixture of neomycins A, B, and C produced by Streptomyces fradiae; see also ! Antibiotics [19]. Framycetin sulfate has broad-spectrum activity similar to that of neomycin but is more efficacious against Pseudomonas spp.…”

A Convenient Synthesis of Alkoxycyclopropanes

“…I t is very likely that first one chlorine atom of the dichloromethyl alkyl ether is exchanged for iodine in a nucleophilic reaction, then a halogen-metal exchange with the methyllithium takes place with formation of a lithiochloromethyl alkyl ether, the latter then decomposing to form alkoxy-carbene and lithium chloride. Finally, the carbene adds onto the olefinic double bond [2]. …”

“…Distillation yields 12.7 g of I-vinyl-2-n-hexoxycyclopropane, b. p. 122 OC/65 mm (isomer ratio 1.3 : 1). Two 2,6-diamino-2,6-dideoxyhexoscs were isolated from Neomycin B [2] and Paromomycin [3] which proved to be identical [4] and for which the constitution of 2,6-diamino-2,6dideoxy-L-idose was proposed [5].The proof of this structure 161 by degradation to 5-acetamino-5-deoxy-L-xylofuranose prompts us to report its synthesis. Treatment of the blocked oxazoline ( I ) [7] with 5 x 10-4 N niethanolic hydrochloric acid [8] gave methyl 2-benzamino-2-deoxy-3-0-methyl-~-o-glucofuranoside(2) in excellent yield.…”

“…Chromatographic purification produced a colorless hygroscopic powder, [a]? = +17.8" (c = 1.18 in water); [2,3] give which crystallized in large prisms, n1.p. 148--149 'C; [3] gives 150.5-151.5 'C; = -19.2" (c = 0.5 in water); [3] gives -17.8 (c = 4.0 in acetate buffer).…”