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Abstract

A novel principle for asymmetric induction using a single chiral auxiliary has been developed in this work: the spiro concept. It is based on the combination of an auxiliary with a photochemically reactive site, an enone- like chromophore, via a spirocyclic arrangement. The value of the concept has been probed in inter- and intramolecular "it de Mayo/"-type (2+2) photocycloadditions. Enone chromophores attached to (-)- methone and (+)-camphor (underline1 and underline2, respectively) have been prepared and photochemically reacted. A side selection of up to 14:1 with an invariable preference for face "it a vs. b/" has been observed for the (-)-menthone derivatives. Negligible induction is found for the camphor-derived dioxacyclohexenones. Notably, the method has an inherent advantage since preferential "it a/"-side diastereoselection is obtained for both enones of the menthone series, (-)-underline"1a" and (-)- underline"1b" which allows to select complementary series of final enantiomeric products by using one enantiomer of the auxiliary only. In the first example of application the pheromone (+)- grandisol has been synthesized "it via/" (+)- underline"17a" in merely five steps, constituting the hitherto shortest access to this natural product. 5-Alkenyl derivatives of (-)-underline"1a", (-)- underline"40" and (-)-underline"41", have been synthesized and their photoreactivity has been probed. While high levels of regioselection towards straight'' products were observed, no conclusive information on the face selectivity could yet be obtained.

Additional information

Authors: BENET A P UNIVERSITAET, GHS, ESSEN (GERMANY) - FACHBEREICH CHEMIE, UNIVERSITAET, GHS, ESSEN (GERMANY) - FACHBEREICH CHEMIE
Bibliographic Reference: PUBLISHED BY MAX-PLANCK-INSTITUT FUER STRAHLENCHEMIE, MUELHEIM A.D. RUHR (GERMANY) SCHRIFTENREIHE DES MAX-PLANCK-INSTITUTS FUER STRAHLENCHEMIE, NR. 36, 1988
Record Number: 1989126110700 / Last updated on: 1989-06-01
Category: PUBLICATION
Available languages: en
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