Preparative Organic Chemistry
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ChemInform Abstract: Potentially Aromatic Thiophenium Ylides. Part 4. Formation and Cyclization of Methyl- and Methoxycarbonyl Substituted 2-(2′-Thienyl)benzoylcarbenes.
First published: September 2, 1986
Abstract
The diazo compounds (X) are prepared from (I) via (III) and (V) as shown in the scheme.
ChemInform Abstract
The diazo compounds (X) are prepared from (I) via (III) and (V) as shown in the scheme. Catalytic decomposition of (X) using rhodium(II) acetate yields the thiopyrans (XII) accompanied by (XIII), (XIV) or (XV)/(XVI) (the latter two compounds being isolated in the form of their enoI methyl ether). It seems likely that all products arise from the same type of intermediate, viz. the ylides (XI) formed by cyclization of the title carbenes.
