A photoinduced two carbon ring expansion leading to an easy synthesis of γ-tropolone

M Cavazza, F Pietra

Index: Cavazza, Marino; Pietra, Francesco Journal of the Chemical Society, Chemical Communications, 1986 , # 19 p. 1480 - 1481

Full Text: HTML

Citation Number: 4

Abstract

Irradiation of 3-methoxycyclopent-2-en-1-one (1) and an excess of acetylene in MeCN at 0° C with Pyrex-filtered light from a Hg-lamp gives 5-methoxycyclohepta-2, 4-dien-1-one (2), which undergoes SeO2 oxidation to 4-methoxytropone (3), a known source of γ-tropolone (4); using dideuterioacetylene in place of acetylene, a 3: 2 mixture of the isomeric 2, 3-and 3, 4-dideuterio analogues of (2) is obtained, suggesting a limitation of this method for ...