Novel and Efficient Insertions of Carbons Carrying O-, S-, and N-Linked Substituents:  Synthesis of α-Alkoxyalkyl, α-(Alkylthio)alkyl, and α-(Carbazol-9-yl)alkyl Ketones

• Published in: Journal of organic chemistry Vol. 61; no. 21; pp. 7564 - 7570
• Main Authors: Katritzky, Alan R, Xie, Linghong, Serdyuk, Larisa
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 18.10.1996; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Organic; Physical Sciences; Science & Technology; CYCLIC-KETONES; ORGANIC-SYNTHESIS; SULFOXIDES; ANION EQUIVALENT; RING EXPANSION; DIAZOALKANES; SULFENYLATION; ALDEHYDES; HOMOLOGATION; BENZOTRIAZOLE
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo960840p

A wide variety of benzotriazolyl-stabilized anions 2, obtained by the lithiation of 1-(α-alkoxyalkyl)-, 1-[α-(alkylthio)alkyl]-, and 1-[α-(carbazol-9-yl)alkyl]benzotriazoles 1, on reaction with aliphatic and aromatic aldehydes and ketones, followed by rearrangement induced by heating in the presence of zinc bromide, furnish one-carbon-homologated α-alkoxyalkyl, α-(alkylthio)alkyl, and α-(carbazol-9-yl)alkyl ketones 4 in simple one-pot operations in good yields with excellent regioselectivity. In several alkoxymethylene insertions, intermediate 2-alkoxyoxiranes were separated in good yields, demonstrating the epoxide mechanism for the rearrangements and providing a facile approach to polysubstituted 2-alkoxyoxiranes, another class of important compounds.