ABSTRACT
In the course of our studies on the regioselective carbon-oxygen bond cleavage of the benzylidene acetal group of hexopyranosides with a reducing agent, we found that a combination of a Lewis acid and a reducing agent triggered a ring-opening reaction of the pyranose ring of methyl α-D-allopyranosides. The formation of an acyclic boronate ester by the attachment of a hydride ion at C-1 indicated that the unexpected endocyclic cleavage of the bond between the anomeric carbon atom and the pyranose ring oxygen atom proceeded via an oxacarbenium ion intermediate produced by the chelation between O5/O6 of the pyranoside and the Lewis acid, followed by nucleophile substitution with a hydride ion at C1.
Subject(s)
Boron Compounds/chemistry , Glycosides/chemistry , Glycosides/chemical synthesis , Silanes/chemistryABSTRACT
We report a case of verrucous carcinoma of the penis. A 62-year-old man, who presented with penile swelling and pain, was referred to our hospital. Although, penile tumor biopsy revealed no evidence of malignancy, the patient presented with penile swelling and discharge. The penis was surgically resected and urinary diversion was performed. The pathological examination of the resected glans revealed verrucous carcinoma of penis. Furthermore, in situ hybridization revealed human papilloma virus (HPV) infection. This clearly showed that the verrucous carcinoma of the penis resulted from the HPV infection. The patient has survived for 14 months after surgery without local recurrence or metastasis.
