[A case of gastric carcinosarcoma treated with surgical resection and irinotecan and mitomycin C combination therapy].

A 59-year-old man was admitted following episodes of melena. Upper gastrointestinal endoscopy revealed a type 2 carcinoid-like tumor in the cardium of the stomach. Histopathological analysis of a biopsy specimen revealed adenocarcinoma. Although hepatic metastases were detected, total gastrectomy was initially performed for hemorrhage control. The final histopathological diagnosis of the resected primary tumor was gastric carcinosarcoma with an osteosarcoma component. After ineffective first-line combination therapy with S-1 (tegafur, gimeracil, and oteracil) and cisplatin, irinotecan and mitomycin C chemotherapy was introduced. Although the hepatic metastases showed shrinkage after three courses of the chemotherapy, the patient succumbed seven months after surgery. This case report suggests that systemic chemotherapy using irinotecan and mitomycin C may be effective in the treatment of gastric carcinosarcoma with an osteosarcoma component and distant metastases.

Nucleophilic 5-endo-trig cyclizations of N-homoallylic sulfonamides: a facile method for the construction of pyrrolidine rings.

Normally disfavored 5-endo-trig cyclizations proceed in N-homoallylsulfonamides bearing a CF(3), CCl(3), CO(2)Et or CN group at the C-3 position, via an intramolecular S(N)2'-type or addition reaction to construct pyrrolidine rings, even though the system allows a more favorable 5-exo-trig pathway.

A new class of substrates for nucleophilic 5-endo-trig cyclization, 2-trifluoromethyl-1-alkenes: synthesis of five-membered hetero- and carbocycles that bear fluorinated one-carbon units.

Disfavored 5-endo-trig cyclizations were achieved in 2-trifluoromethyl-1-alkenes with a nucleophilic nitrogen, oxygen, sulfur, or carbon atom through 1) intramolecular S(N)2' reaction with loss of a fluoride ion or 2) intramolecular nucleophilic addition to the vinylic group. This reaction manifold provides a versatile method for the synthesis of indolines, indoles, pyrrolidines, tetrahydrofurans, 2,3-dihydrobenzo[b]thiophenes, tetrahydrothiophenes, and cyclopentanes that bear a fluorinated one-carbon unit such as a difluoromethylene, difluoromethyl, or trifluoromethyl group.

Divergent chemical synthesis of prolines bearing fluorinated one-carbon units at the 4-position via nucleophilic 5-endo-trig cyclizations.

N-[3-(Trifluoromethyl)homoallyl]sulfonamides, prepared via ring opening of (S)-glycidyl ethers or 2-aryloxiranes with 1-(trifluoromethyl)vinyllithium, underwent intramolecular addition or S(N)2'-type reaction in the normally disfavored 5-endo-trig fashion, leading to 2-substituted 4-(trifluoromethyl)- or 4-(difluoromethylene)pyrrolidines. Both alpha- and beta-face-selective hydrogenation of the 4-difluoromethylene group afforded syn- and anti-4-(difluoromethyl)pyrrolidines, respectively. These sequences, followed by the oxidation of a 2-hydroxymethyl or 2-aryl group, successfully provided prolines with a trifluoromethyl, difluoromethylene, or difluoromethyl group at the 4-position, including optically active prolines.