𝔖 Bobbio Scriptorium
✦   LIBER   ✦

A novel approach to periplanone-b involving an intramolecular Diels-Alder reaction with furan-diene and allene-dienophile

✍ Scribed by Serge G. Cauwberghs; Pierre J. De Clercq

Publisher
Elsevier Science
Year
1988
Tongue
French
Weight
289 KB
Volume
29
Category
Article
ISSN
0040-4039

No coin nor oath required. For personal study only.

✦ Synopsis

The 6-step sequence to trienone 2, a known intermediate for the total synthesis of periplanone-B, involves the conversion of 2 into 5 using dilithiated propadiene, the IMDA of 4 to E-adducts 1 and 6, the conversion of 2 to diol S via a radical anion promoted cleavage of the oxygen bridge, and a in-situ low temperature Grob fragmentation to 2.

After the discovery in 1952 that females of the species Periplanata americana, the American cockroach, produce a very potent sex excitant,2 two extremely active compounds, periplanones -A and -B, were isolated by Persoons, and a germacranoid structure proposed for the latter.

3 The unambiguous structural assignment of periplanone-B as 1 resulted from the pioneering work of Still, that culminated in the first total synthesis of (*)-1. 4 Later total syntheses of (+)-l_ were reported by Schreiber, 5 Hauptmann and Walker,' Takahashi,'

and of natural (-)-1 by Kitahara. 8 In these approaches the construction of the lo-membered

πŸ“œ SIMILAR VOLUMES

Intramolecular diels-alder reaction with
Intramolecular diels-alder reaction with furan-diene. A novel potential entry to steroids.
✍ Luc A. Van Royen; Roelant Mijngheer; Pierre J. De Clercq πŸ“‚ Article πŸ“… 1982 πŸ› Elsevier Science 🌐 French βš– 238 KB

Depending on the reaction conditions the intramolecular Diels-Alder reaction of furan-diene 14 yields predominantly either one of two adducts 16a and 16b , which possess the necessary --functionality for eventual transformation into corticosteroids. The dienophile was intro-

Intramolecular Diels-Alder Reaction with
Intramolecular Diels-Alder Reaction with Furan-Diene. 1. A Novel Entry to the BCD-Ring System of 11-Ketosteroids
✍ Luc A. van Royen; Roelant Mijngheer; Pierre J. De Clercq πŸ“‚ Article πŸ“… 2010 πŸ› Wiley (John Wiley & Sons) βš– 1012 KB

A novel Approach f o r t h e s y n t h e s i s of t h e BCD-ring system i n s t e r o i d s i s d e s c r i b e d . The sequence centers about t h e i n t r a m o l e c u l a r Diels-Alder r e a c t i o n of f u r a n 1 5 , which, depending on t h e r e a c t i o n c o n d i t i o n s , l e a d s pr