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Synthesis of steroid precursors. Intramolecular Diels-Alder approach to the trans-hydrindenone system.

โœ Scribed by Swati A. Bal; Paul Helquist

Publisher
Elsevier Science
Year
1981
Tongue
French
Weight
243 KB
Volume
22
Category
Article
ISSN
0040-4039

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โœฆ Synopsis

Diels-Alder reaction of the 1,3-propanediol-derived ketal of (6E)-2-methyl-1,6,8-nonatrien-3-one produces an approximately 3:l ratio of trans-and cis-hydrindenones.

Very recently we have reported a new annulation procedure for the fusion of dihydro-and tetrahydro-naphthalene ring systems onto other carbon frameworks through the use of ortholithiated g-phenethyl halides (l).l Among the several important classes of natural products for which this method may be employed in total synthesis, the steroids, and most clearly the ring A aromatic compounds (e.g. the estrogens), may serve as especially attractive applica-

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