Preparation and polymerization of a diisocyanate from the Diels-Alder adduct of levopimaric acid and acrylic acid

1972 ◽  
Vol 10 (3) ◽  
pp. 921-929 ◽  
Author(s):  
John F. Bingham ◽  
C. S. Marvel
Keyword(s):  
Acrylic Acid ◽  
Diels Alder ◽  
Levopimaric Acid ◽  
Alder Adduct

Rearrangements in the Diterpenoid Series. I. The Solvolysis of Methyl 15β-tosyloxy-13-isopropyl-17-noratis-13-en-18-oate

1973 ◽  
Vol 51 (1) ◽  
pp. 77-86 ◽  
Author(s):  
William A. Ayer ◽  
Pandurang D. Deshpande
Keyword(s):  
Diels Alder ◽  
Vinyl Ketone ◽  
Methyl Vinyl Ketone ◽  
Unsaturated Ketone ◽  
Methyl Vinyl ◽  
Levopimaric Acid ◽  
Alder Adduct

The synthesis of methyl 15β-hydroxy-13-isopropyl-17-noratis-13-en-18-oate (14b) is described. Compound 14b was prepared from the ketone 12b, in turn derived from the Diels–Alder adduct formed between levopimaric acid (7) and α-acetoxyacrylonitrile. Solvolysis of the tosylate of 14b proceeds predominantly with rearrangement and elimination to give methyl 16-isopropylidene-7,17-secoacon-8(15)-en-18-oate (16a). This rearrangement serves as a model for the proposed biosynthetic transformation of atisine-type alkaloids into alkaloids of the aconitine series. The degradation of 16a into the unsaturated ketone 19, which contains the 19 carbons of the aconane skeleton, is described. The Diels–Alder addition of methyl vinyl ketone to levopimaric acid is reported and the adduct is shown to possess structure 8.

C-Nucleosides and related compounds. VI. Carbocyclic analogues of C-nucleosides: synthesis and derivatives of some useful intermediates

1976 ◽  
Vol 54 (6) ◽  
pp. 849-860 ◽  
Author(s):  
George Just ◽  
Grant Reader ◽  
Bernadette Chalard-Faure
Keyword(s):  
Acrylic Acid ◽  
Wittig Reaction ◽  
Diels Alder ◽  
Reaction Products ◽  
Free Aldehyde ◽  
Derivatives Of ◽  
Related Compounds ◽  
Alder Adduct

The Diels–Alder adduct of cyclopentadiene and β-bromo acrylic acid 1 was converted to D,L-exo-6,7-(dihydroxy-di-O-isopropylidene)-2-hydroxy-3-oxabicyclo[3.2.1]octane (9) in an eight-step sequence and a 24% yield based on 1. Alternatively, the hemiacetal 9 was obtained in five steps and 22% yield from norbornadiene through the intermediate lactone 11. The thiosemicarbazone and semicarbazone of 9 were prepared. The synthesis of the free aldehyde 13 as well as that of the Wittig reaction products 12 and 19 are described.

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