2H-1-Benzopyrans. II. 4-Chloro-3-methoxycarbonyl-2-dimethoxyphosphoryl-2H-1-benzopyran, (I), and 4-Chloro-2-dimethoxyphosphoryl-2H-1-benzopyran, (II)

The pyranoid rings are in a half-boat conformation in compound (I), C₁₃H₁₄ClO₆P, and in a deformed half-boat towards half-chair conformation in compound (II), C₁₁H₁₂ClO₄P. Fusion with the pyranoid ring has no significant influence on the planarity of the benzene ring in either compound. In both structures the dimethoxyphosphoryl group is attached axially and the presence of the methoxycarbonyl substituent in (I) seems responsible for the disorder observed in the dimethoxyphosphoryl group.

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