(‐)‐(S)‐2‐Chloro‐3‐(5‐imidazolyl)propanol (4) was synthesized by reduction of both the acid chloride and the methyl ester of (‐)‐(S)‐2‐chloro‐3‐(5‐imidazolyl)propionic acid. The optical rotatory dispersion and circular dichroism spectra are discussed.

Furoquinoline and pyranoquinoline alkaloids have been synthesized in some cases via the 2,3-dihydrofuroquinoline and 3,4-dihydropyranoquinoline intermediates, respectively. Dehydrogenation is possible in low yields either by heating in the presence of palladium on charcoal' or through bromination with N-bromosuccinimide followed by dehydrobromination2.An easy conversion of the readily accessible dihydr~flindersine~,~ (I) to the alkaloid flindersine (11) from Flindersiu australis R.Br. has been described by Piozzi et aL4 Dehydrogenation occurs on treatment with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in boiling benzene.Attempts to convert in this way the alkaloid khaplofoline, 2,2-dimethyl-5-oxo-2,3,5,10-tetrahydropyrano[2,3-b]quinoline (111), to the linear isomer of flindersine yielded, unexpectedly, flindersine according to the melting point, nmr, and uv spectra. The identity was proved by comparison of the infrared spectrum with that of flindersine, prepared by known methods4.

Khaplofolin (I), das in 30%iger Ausbeute aus α‐Anilinocarbonyl‐ry‐isopropyl‐ry‐butyrolacton zugänglich ist, liefert bei der Dehydrierung mit 2,3‐Dichlor‐5,6‐dicyan‐benzochinon (DDQ) nicht das erwartete lineare Isomere von Flindersin, sondern Flindersin (II) selbst, das identisch mit dem Dehydrierungsprodukt von Dihydro?indersin (III) ist.

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