α-Hydroxycyclobutane rearrangement followed by retroaldol cleavage: A novel and powerful technology for the stereocontrolled construction of carbocyclic systems. An easy access to angularly functionalised trans-fused cycloheptanoids
✍ Scribed by Rupak Chakraborty; Manas K. Basu; Brindaban C. Ranu
- Publisher
- Elsevier Science
- Year
- 1992
- Tongue
- French
- Weight
- 386 KB
- Volume
- 48
- Category
- Article
- ISSN
- 0040-4020
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✦ Synopsis
Acid-catalysed rearrangement of a-hydroxycyclobutane derivatives 7a-7c and lla-llc followed by retroaldol cleavage and oxidation in a single operation furnish angularly carboxylated trans-fused cycloheptanoid derivatives 9a-9c and 12a-12c in good yields. During the last few years a wide variety of natural products bearing angularly functionalised trans-fused seven-membered ring systems as the core of their polycarbocyclic frameworks have been isolated1 from marine, plant, insect and microbial sources and many of them have been shown to possess promising biological activities. A few representative examples of current interest are phorboids 1.' virgenes 2. 3 reiswigins 3,4 and helenanolides 4. 5